Jump to content

Nylon-eating bacteria: Difference between revisions

From Wikipedia, the free encyclopedia
Content deleted Content added
see also
Citation bot (talk | contribs)
Add: bibcode, doi-access. Removed URL that duplicated identifier. | Use this bot. Report bugs. | Suggested by Abductive | [[Category:Biological evolution] | #UCB_Category 28/40
 
(244 intermediate revisions by more than 100 users not shown)
Line 1: Line 1:
{{Short description|Species of bacteria}}
In 1975 a team of Japanese scientists discovered a strain of ''[[Flavobacterium]]'' living in ponds containing waste water from a factory producing [[nylon]] that was capable of digesting certain byproducts of nylon-6 manufacture, such as, 6-aminohexanoate linear dimer, even though those byproducts had not existed prior to the invention of nylon in 1935. Further study revealed that the three [[enzyme]]s the [[bacteria]] were using to digest the byproducts were novel, significantly different from any other enzymes produced by other ''Flavobacterium'' strains (or any other bacteria for that matter), and not effective on any other material other than the man made nylon byproducts. <ref> Kinoshita, S., Kageyama, S., Iba, K., Yamada, Y. and Okada, H. 1981 </ref> This strain of Flavobacterium, Sp. K172, became popularly known as nylon eating bacteria, and the enzymes were collectively known as nylonase.
{{Infraspeciesbox
| name = Nylon-eating bacteria
| genus = Paenarthrobacter
| species = ureafaciens
| varietas = KI72
| authority = [[Genome Taxonomy Database|GTDB]] r95 & NCBI, 2020 (Busse HJ, 2016)
| synonyms =
* ''Arthrobacter'' sp. KI72<br/><small>Takehara I, 2017<ref name=genome>{{cite journal |last1=Takehara |first1=I |last2=Kato |first2=DI |last3=Takeo |first3=M |last4=Negoro |first4=S |title=Draft Genome Sequence of the Nylon Oligomer-Degrading Bacterium ''Arthrobacter'' sp. Strain KI72. |journal=Genome Announcements |date=27 April 2017 |volume=5 |issue=17 |doi=10.1128/genomeA.00217-17 |pmid=28450506 |pmc=5408104 |doi-access=free}}</ref></small>
* ''Flavobacterium'' sp. KI72<br/><small>Negoro S, 1980</small>
* ''Achromobacter guttatus'' KI72<br/><small>Kinoshita S, 1975</small>


(Due to an [[Optical character recognition|OCR]] error, the strain name has occasionally been reported as "K172".)
== Further research ==
}}


'''''Paenarthrobacter ureafaciens'' KI72''', popularly known as '''nylon-eating bacteria''', is a [[strain (biology)|strain]] of ''[[Paenarthrobacter ureafaciens]]'' that can digest certain [[by-product]]s of [[nylon 6]] manufacture.<ref name=Takehara>{{cite journal | title=Metabolic pathway of 6-aminohexanoate in the nylon oligomer-degrading bacterium Arthrobacter sp. KI72: identification of the enzymes responsible for the conversion of 6-aminohexanoate to adipate | last1=Takehara | first1=I | last2=Fujii | first2=T | last3=Tanimoto | first3=Y | journal=Applied Microbiology and Biotechnology | date=Jan 2018 | volume=102 | issue=2 | pages=801–814 | pmid=29188330 | doi=10.1007/s00253-017-8657-y | s2cid=20206702 }}</ref> It uses a set of [[enzyme]]s to digest nylon, popularly known as '''nylonase'''.<ref>{{cite web | url=https://www.newscientist.com/article/dn16834-five-classic-examples-of-gene-evolution/ |author=Michael Le Page |title=Five classic examples of gene evolution |date=March 2009 |website=New Scientist |access-date= |quote=}}</ref>
Scientists were able to induce another species of bacteria, ''[[Pseudomonas aeruginosa]]'', to evolve the capability to break down the same nylon byproducts in a laboratory by forcing them to live in an environment with no other source of nutrients. The ''P. aeruginosa'' strain did not seem to use the same enzymes that had been utilized by the original ''[[Flavobacterium]]'' strain. <ref>Prijambada, ''et al.'' "Emergence of Nylon Oligomer Degradation Enzymes in ''Pseudomonas aeruginosa'' PAO through Experimental Evolution." ''Applied and Environmental Microbiology.'' Vol. 61, No. 5 (May 1995) p. 2020–22 PMID 7646041</ref> Other scientists were able to get the ability to generate the enzymes to transfer from the ''Flavobacterium'' strain to a strain of ''[[E.Coli]]'' bacteria via a [[plasmid]] transfer. <ref> Negoro S, Taniguchi T, Kanaoka M, Kimura H, Okada H. 1983 </ref> Genetic analysis of the plasmid led some scientists to the conclusion that the genes to produce one of the enzymes had most likely resulted from the combination of a [[gene duplication]] event with a [[frame shift mutation]]. <ref> Susumu Ohno 1984 </ref> Further analysis has led to speculation that the fact that the frame shift was able to produce a functioning enzyme was related to the absence of stop [[codon]]s in the duplicate gene.<ref>Yomo, T., Urabe, I. and Okada, H., 1992 </ref> Research has continued in the hope of better understanding the mechanisms involved in the [[evolution]] of new enzymes, and because of the possible value of bacteria that can metabolize man made molecules to toxic waste cleanup.


==Discovery and nomenclature ==
== Role in creation-evolution controversy ==
[[File:6-Aminocaproic acid.png|thumb|Chemical structure of [[Aminocaproic acid|6-aminohexanoic acid]]]]
In 1975, a team of Japanese scientists discovered a strain of bacterium, living in ponds containing [[Wastewater|waste water]] from a [[nylon]] factory, that could digest certain byproducts of [[nylon 6]] manufacture, such as the linear dimer of [[Aminocaproic acid|6-aminohexanoate]]. These substances are not known to have existed before the invention of [[nylon]] in 1935. It was initially named as ''[[Achromobacter]] guttatus''.<ref>{{cite journal | author = Kinoshita, S. |author2=Kageyama, S. |author3=Iba, K. |author4=Yamada, Y. |author5=Okada, H. |title=Utilization of a cyclic dimer and linear oligomers of e-aminocaproic acid by Achromobacter guttatus KI 72 |journal=Agricultural and Biological Chemistry |volume=39 |issue=6 |pages=1219–23 |year=1975 |issn=0002-1369 |doi=10.1271/bbb1961.39.1219|doi-access=free }}</ref>


Studies in 1977 revealed that the three [[enzyme]]s that the [[bacteria]] were using to digest the byproducts were significantly different from any other enzymes produced by any other bacteria, and not effective on any material other than the manmade nylon byproducts.<ref>{{Cite journal|title=6-Aminohexanoic Acid Cyclic Dimer Hydrolase. A New Cyclic Amide Hydrolase Produced by Achromobacter Guttatus KI74|last1=S|first1=Kinoshita|last2=S|first2=Negoro|date=1977-11-01|journal=European Journal of Biochemistry|language=en|pmid=923591|last3=M|first3=Muramatsu|last4=Vs|first4=Bisaria|last5=S|first5=Sawada|last6=H|first6=Okada|volume=80|issue=2|pages=489–95|doi=10.1111/j.1432-1033.1977.tb11904.x}}</ref>
Nylon eating bacteria have been widely discussed in the context of the [[creation-evolution controversy]]. Organizations critical of [[creationism]] and [[intelligent design]], such as the [[National Center for Science Education]], and New Mexicans for Science and Reason (NMSR) have made extensive references to this research in postings on their websites, arguing that this research refutes claims made by creationists and intelligent design proponents, specifically, the statement that random mutation and natural selection can never add new information to a [[genome]], and the statement that the odds against a useful new [[protein]] such as an enzyme arising through a process of random mutation would be prohibitively high.<ref>[http://www.talkorigins.org/indexcc/CB/CB101_2.html| Claim CB101_2] and claim [http://www.talkorigins.org/indexcc/CB/CB102.html CB102] in the [[Talk Origins Archive]]</ref> <ref>[http://www.nmsr.org/nylon.htm New Mexicans for Science and Reason article about nylon eating bacteria] </ref>Creationists have disputed these conclusions, often citing analysis posted on the [[Answers in Genesis]] website that says that this phenomenon was evidence that plasmids in bacteria were a designed feature intended to allow bacteria to adapt easily to new food sources or cope with toxic chemicals.<ref>[http://www.answersingenesis.org/tj/v17/i3/bacteria.asp Answers in Genesis article on nylon eating bacteria]</ref> NMSR, among others, has responded by saying that gene duplication and frame shift mutations were powerful sources of random [[mutation]].<ref>[http://www.nmsr.org/nylon.htm New Mexicans for Science and Reason article about nylon eating bacteria] </ref> In particular, proof that it was ''these'' mutations that gave rise to nylonase, rather than the process based on plasmids suggested by AiG, has been obtained from DNA sequencing.<ref> [http://www.nmsr.org/nylon.htm#update update] to NMSR website.

The bacterium was reassigned to ''[[Flavobacterium]]'' in 1980.<ref>{{cite journal |last1=Negoro |first1=S |last2=Shinagawa |first2=H |last3=Nakata |first3=A |last4=Kinoshita |first4=S |last5=Hatozaki |first5=T |last6=Okada |first6=H |title=Plasmid control of 6-aminohexanoic acid cyclic dimer degradation enzymes of Flavobacterium sp. KI72. |journal=Journal of Bacteriology |date=July 1980 |volume=143 |issue=1 |pages=238–45 |doi=10.1128/JB.143.1.238-245.1980 |pmid=7400094 |pmc=294219 |doi-access=free}}</ref> Its genome was resolved in 2017, again reassigning it to ''[[Arthrobacter]]''.<ref name=genome/> The [[Genome Taxonomy Database]] considers it a strain of ''[[Paenarthrobacter ureafaciens]]'' following a 2016 reclassification.<ref>{{cite web |title=GTDB - GCF_002049485.1 |url=https://gtdb.ecogenomic.org/genomes?gid=GCF_002049485.1 |website=Genome Taxonomy Database, revision 95|date=2020}}</ref> As of January 2021, the [[National Center for Biotechnology Information|NCBI]] taxonomy browser has been updated to match GTDB.

=== Descendant strains ===
A few newer strains have been created by growing the original KI72 in different conditions, forcing it to adapt. These include KI722, KI723, KI723T1, KI725, KI725R, and many more.<ref>{{cite journal |last1=Negoro |first1=S |last2=Kakudo |first2=S |last3=Urabe |first3=I |last4=Okada |first4=H |title=A new nylon oligomer degradation gene (nylC) on plasmid pOAD2 from a Flavobacterium sp. |journal=Journal of Bacteriology |date=1992 |volume=174 |issue=24 |pages=7948–7953 |doi=10.1128/jb.174.24.7948-7953.1992|pmid=1459943 |pmc=207530 |doi-access=free }}</ref>

== The enzymes ==
The bacterium contains the following three enzymes:

* [[6-aminohexanoate-cyclic-dimer hydrolase]] (EI, ''NylA'', {{UniProt|P13398}})
* [[6-aminohexanoate-dimer hydrolase]] (EII, ''NylB'', {{UniProt|P07061}})
* [[6-aminohexanoate-oligomer endohydrolase]] (EIII, ''NylC'', {{UniProt|Q57326}})

All three enzymes are encoded on a [[plasmid]] called pOAD2.<ref name=e2-mech/> The plasmid can be transferred to ''[[E. coli]]'', as shown in a 1983 publication.<ref>
{{cite journal
|vauthors= Negoro S, Taniguchi T, Kanaoka M, Kimura H, Okada H
|title= Plasmid-determined enzymatic degradation of nylon oligomers
|journal= J. Bacteriol. |volume= 155 |issue= 1 |pages= 22–31
|date= July 1983 |doi= 10.1128/JB.155.1.22-31.1983
|pmid= 6305910 |pmc= 217646
|url= }}
</ref>
</ref>


== Notes ==
=== EI ===
The enzyme EI is related to [[amidase]]s. Its structure was resolved in 2010.<ref>{{cite journal |last1=Yasuhira |first1=K |last2=Shibata |first2=N |last3=Mongami |first3=G |last4=Uedo |first4=Y |last5=Atsumi |first5=Y |last6=Kawashima |first6=Y |last7=Hibino |first7=A |last8=Tanaka |first8=Y |last9=Lee |first9=YH |last10=Kato |first10=D |last11=Takeo |first11=M |last12=Higuchi |first12=Y |last13=Negoro |first13=S |title=X-ray crystallographic analysis of the 6-aminohexanoate cyclic dimer hydrolase: catalytic mechanism and evolution of an enzyme responsible for nylon-6 byproduct degradation. |journal=The Journal of Biological Chemistry |date=8 January 2010 |volume=285 |issue=2 |pages=1239–48 |doi=10.1074/jbc.M109.041285 |pmid=19889645 |pmc=2801252 |doi-access=free}}</ref>
<div class="references-small">
<references />
</div>


== References ==
=== EII ===
EII has evolved by gene duplication followed by base substitution of another protein EII'. Both enzymes have 345 identical aminoacids out of 392 aminoacids (88% homology). The enzymes are similar to [[beta-lactamase]].<ref>{{Cite journal|last1=Okada|first1=H.|last2=Negoro|first2=S.|last3=Kimura|first3=H.|last4=Nakamura|first4=S.|date=10–16 November 1983|title=Evolutionary adaptation of plasmid-encoded enzymes for degrading nylon oligomers|journal=Nature|volume=306|issue=5939|pages=203–206|doi=10.1038/306203a0|issn=0028-0836|pmid=6646204|bibcode=1983Natur.306..203O|s2cid=4364682}}</ref>
* Kinoshita, S., Kageyama, S., Iba, K., Yamada, Y. and Okada, H., Utilization of a cyclic dimer and linear oligomers of ε-aminocapronoic acid by Achromobacter guttatus K172, Agric. Biol. Chem. 116, 547-551 (1981), FEBS 1981
* Yomo, T., Urabe, I. and Okada, H., [http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=525574 No stop codons in the antisense strands of the genes for nylon oligomer degradation], Proceedings of the National Academy of Sciences USA 89:3780–3784, 1992
* IRFAN D. PRIJAMBADA, SEIJI NEGORO, TETSUYA YOMO, AND ITARU URABE, [http://aem.asm.org/cgi/reprint/61/5/2020.pdf#search=%22Irfan%20nylon%20Pseudomonas%22 Emergence of Nylon Oligomer Degradation Enzymes in Pseudomonas aeruginosa PAO through Experimental Evolution PDF], APPLIED AND ENVIRONMENTAL MICROBIOLOGY, May 1995
* Susumu Ohno, [http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=345072 Birth of a unique enzyme from an alternative reading frame of the preexisted, internally repetitious coding sequence], Proc. Natl. Acad. Sci. USA Vol. 81, pp. 2421-2425, April 1984
* Negoro S, Taniguchi T, Kanaoka M, Kimura H, Okada H. Plasmid-determined enzymatic degradation of nylon oligomers. Journal of Bacteriology. July 1983


The EII' (''NylB''', {{UniProt|P07062}}) protein is about 100x times less efficient compared to EII. A 2007 research by the [[Seiji Negoro]] team shows that just two amino-acid alterations to EII', i.e. G181D and H266N, raises its activity to 85% of EII.<ref name=e2-mech>{{cite journal |vauthors= Negoro S, Ohki T, Shibata N, etal |title= Nylon-oligomer degrading enzyme/substrate complex: catalytic mechanism of 6-aminohexanoate-dimer hydrolase |journal= J. Mol. Biol. |volume= 370 |issue= 1 |pages= 142–56 |date= June 2007 |pmid= 17512009 |doi= 10.1016/j.jmb.2007.04.043 }}</ref>
== External links ==
* [http://www.nmsr.org/nylon.htm Evolution and Information: The Nylon Bug]
* [http://www.ncseweb.org/resources/articles/4661_issue_16_volume_5_number_2__4_10_2003.asp#New%20Proteins%20Without%20God's%20Help New Proteins Without God's Help] &ndash; William M. Thwaites
* [http://www.answersingenesis.org/tj/v17/i3/bacteria.asp?vPrint=1 AnswersInGenesis.org &ndash; The adaptation of bacteria to feeding on nylon waste]


=== EIII ===
[[Category:Evolution]]
The structure of EIII was resolved in 2018. Instead of being a completely novel enzyme, it appears to be a member of the N-terminal nucleophile (N-tn) hydrolase family.<ref name=Negoro>{{cite journal |last1=Negoro |first1=S |last2=Shibata |first2=N |last3=Lee |first3=YH |last4=Takehara |first4=I |last5=Kinugasa |first5=R |last6=Nagai |first6=K |last7=Tanaka |first7=Y |last8=Kato |first8=DI |last9=Takeo |first9=M |last10=Goto |first10=Y |last11=Higuchi |first11=Y |title=Structural basis of the correct subunit assembly, aggregation, and intracellular degradation of nylon hydrolase. |journal=Scientific Reports |date=27 June 2018 |volume=8 |issue=1 |pages=9725 |doi=10.1038/s41598-018-27860-w |pmid=29950566|pmc=6021441 |bibcode=2018NatSR...8.9725N |doi-access=free }}</ref> Specifically, computational approaches classify it as a [[MEROPS]] S58 (now renamed P1) hydrolase. The protein is expressed as a precursor, which then cleaves itself into two chains.<ref>{{cite web |title=Q57326 |url=https://www.ebi.ac.uk/interpro/protein/UniProt/Q57326/ |website=InterPro}}</ref><ref>{{Cite web|url=https://www.ebi.ac.uk/merops/cgi-bin/pepsum?id=P01.102|title=MEROPS - the Peptidase Database}}</ref> Outside of this plasmid, >&nbsp;95% similar proteins are found in ''[[Agromyces]]'' and ''[[Kocuria]]''.<ref name=Negoro/>
[[Category:Bacteria]]

[[Category:Creationism]]
EIII was originally thought to be completely novel. [[Susumu Ohno]] proposed that it had come about from the combination of a [[gene duplication|gene-duplication]] event with a [[frameshift mutation]]. An insertion of [[thymidine]] would turn an arginine-rich 427aa protein into this 392aa enzyme.<ref name=":0">{{cite journal |author= Ohno S |title= Birth of a unique enzyme from an alternative reading frame of the preexisted, internally repetitious coding sequence |journal= Proc Natl Acad Sci USA |volume= 81 |issue= 8 |pages= 2421–5 |date= April 1984 |pmid= 6585807 |pmc= 345072 |doi= 10.1073/pnas.81.8.2421|bibcode= 1984PNAS...81.2421O |doi-access= free }}</ref>

==Role in evolution teaching==
{{main|Nylon-eating bacteria and creationism}}
There is scientific consensus that the capacity to synthesize nylonase most probably developed as a single-step mutation that survived because it improved the fitness of the bacteria possessing the mutation. More importantly, one of the enzymes involved was produced by a [[frame-shift mutation]] that completely scrambled existing genetic code data.<ref>{{Cite journal |last=Ohno |first=S |date=April 1984 |title=Birth of a unique enzyme from an alternative reading frame of the preexisted, internally repetitious coding sequence. |journal=Proceedings of the National Academy of Sciences |language=en |volume=81 |issue=8 |pages=2421–2425 |doi=10.1073/pnas.81.8.2421 |doi-access=free |issn=0027-8424 |pmc=345072 |pmid=6585807|bibcode=1984PNAS...81.2421O }}</ref> Despite this, the new gene still had a novel, albeit weak, catalytic capacity. This is seen as a good example of how mutations easily can provide the raw material for [[evolution]] by [[natural selection]].<ref>{{cite journal |author=Thwaites WM |title=New Proteins Without God's Help |journal=Creation Evolution Journal |volume=5 |issue=2 |pages=1–3 |date=Summer 1985 |url=http://ncse.com/cej/5/2/new-proteins-without-gods-help}}</ref><ref>{{cite web |date= |title=Evolution and Information: The Nylon Bug |url=http://www.nmsr.org/nylon.htm |access-date=2023-09-27 |publisher=New Mexicans for Science Education}}</ref><ref>{{Cite web |last=Than |first=Ker |date=2005-09-23 |title=Why scientists dismiss 'intelligent design' |url=https://www.nbcnews.com/id/wbna9452500 |access-date=2023-09-27 |website=NBC News |language=en}}</ref><ref>Miller, Kenneth R. [[Only A Theory|''Only a Theory: Evolution and the Battle for America's Soul'']] (2008) pp. 80-82</ref>

A 1995 paper showed that scientists have also been able to induce another species of bacterium, ''[[Pseudomonas aeruginosa]]'', to evolve the capability to break down the same nylon byproducts in a laboratory by forcing them to live in an environment with no other source of nutrients.<ref>{{cite journal|vauthors=Prijambada ID, Negoro S, Yomo T, Urabe I|date=May 1995|title=Emergence of nylon oligomer degradation enzymes in Pseudomonas aeruginosa PAO through experimental evolution|url= |journal=Appl. Environ. Microbiol.|volume=61|issue=5|pages=2020–2|doi=10.1128/AEM.61.5.2020-2022.1995|pmc=167468|pmid=7646041|bibcode=1995ApEnM..61.2020P}}</ref>


==See also==
==See also==
*[[Plastivore]]
*[[Biodegradable plastic]]
*[[E. coli long-term evolution experiment|''E. coli'' long-term evolution experiment]]
*[[Radiotrophic fungus]]
*[[London Underground mosquito]]
*[[Lonicera fly|''Lonicera'' fly]]
*[[Mealworm]]s are capable of digesting [[polystyrene]]

==References==
{{Reflist|2}}
*{{cite journal |vauthors=Yomo T, Urabe I, Okada H |title=No stop codons in the antisense strands of the genes for nylon oligomer degradation |journal=Proc Natl Acad Sci USA |volume=89 |issue=9 |pages=3780–4 |date=May 1992 |pmid=1570296 |pmc=525574 |doi=10.1073/pnas.89.9.3780|bibcode=1992PNAS...89.3780Y |doi-access=free }}

== External links ==
* [https://www.nite.go.jp/nbrc/catalogue/NBRCCatalogueDetailServlet?ID=NBRC&CAT=00014590 NBRC 14590], information on the KI72 culture maintained at [[National Institute of Technology and Evaluation]]
** [https://www.nite.go.jp/nbrc/catalogue/NBRCCatalogueDetailServlet?ID=NBRC&CAT=00114184 NBRC 114184], a derived culture used in the 2017 sequencing
* {{GO|GO:0019876|label=Nylon catabolic process}}

{{Taxonbar|from=Q4353307}}
{{Authority control}}


[[Category:Biological evolution]]
[[Radiotrophic fungus]]
[[Category:Plastivores]]
[[Category:Actinomycetota]]

Latest revision as of 04:33, 22 May 2024

Nylon-eating bacteria
Scientific classification Edit this classification
Domain: Bacteria
Phylum: Actinomycetota
Class: Actinomycetia
Order: Micrococcales
Family: Micrococcaceae
Genus: Paenarthrobacter
Species:
Variety:
P. u. var. KI72
Trinomial name
Paenarthrobacter ureafaciens var. KI72
GTDB r95 & NCBI, 2020 (Busse HJ, 2016)
Synonyms
  • Arthrobacter sp. KI72
    Takehara I, 2017[1]
  • Flavobacterium sp. KI72
    Negoro S, 1980
  • Achromobacter guttatus KI72
    Kinoshita S, 1975

(Due to an OCR error, the strain name has occasionally been reported as "K172".)

Paenarthrobacter ureafaciens KI72, popularly known as nylon-eating bacteria, is a strain of Paenarthrobacter ureafaciens that can digest certain by-products of nylon 6 manufacture.[2] It uses a set of enzymes to digest nylon, popularly known as nylonase.[3]

Discovery and nomenclature

[edit]
Chemical structure of 6-aminohexanoic acid

In 1975, a team of Japanese scientists discovered a strain of bacterium, living in ponds containing waste water from a nylon factory, that could digest certain byproducts of nylon 6 manufacture, such as the linear dimer of 6-aminohexanoate. These substances are not known to have existed before the invention of nylon in 1935. It was initially named as Achromobacter guttatus.[4]

Studies in 1977 revealed that the three enzymes that the bacteria were using to digest the byproducts were significantly different from any other enzymes produced by any other bacteria, and not effective on any material other than the manmade nylon byproducts.[5]

The bacterium was reassigned to Flavobacterium in 1980.[6] Its genome was resolved in 2017, again reassigning it to Arthrobacter.[1] The Genome Taxonomy Database considers it a strain of Paenarthrobacter ureafaciens following a 2016 reclassification.[7] As of January 2021, the NCBI taxonomy browser has been updated to match GTDB.

Descendant strains

[edit]

A few newer strains have been created by growing the original KI72 in different conditions, forcing it to adapt. These include KI722, KI723, KI723T1, KI725, KI725R, and many more.[8]

The enzymes

[edit]

The bacterium contains the following three enzymes:

All three enzymes are encoded on a plasmid called pOAD2.[9] The plasmid can be transferred to E. coli, as shown in a 1983 publication.[10]

EI

[edit]

The enzyme EI is related to amidases. Its structure was resolved in 2010.[11]

EII

[edit]

EII has evolved by gene duplication followed by base substitution of another protein EII'. Both enzymes have 345 identical aminoacids out of 392 aminoacids (88% homology). The enzymes are similar to beta-lactamase.[12]

The EII' (NylB', P07062) protein is about 100x times less efficient compared to EII. A 2007 research by the Seiji Negoro team shows that just two amino-acid alterations to EII', i.e. G181D and H266N, raises its activity to 85% of EII.[9]

EIII

[edit]

The structure of EIII was resolved in 2018. Instead of being a completely novel enzyme, it appears to be a member of the N-terminal nucleophile (N-tn) hydrolase family.[13] Specifically, computational approaches classify it as a MEROPS S58 (now renamed P1) hydrolase. The protein is expressed as a precursor, which then cleaves itself into two chains.[14][15] Outside of this plasmid, > 95% similar proteins are found in Agromyces and Kocuria.[13]

EIII was originally thought to be completely novel. Susumu Ohno proposed that it had come about from the combination of a gene-duplication event with a frameshift mutation. An insertion of thymidine would turn an arginine-rich 427aa protein into this 392aa enzyme.[16]

Role in evolution teaching

[edit]

There is scientific consensus that the capacity to synthesize nylonase most probably developed as a single-step mutation that survived because it improved the fitness of the bacteria possessing the mutation. More importantly, one of the enzymes involved was produced by a frame-shift mutation that completely scrambled existing genetic code data.[17] Despite this, the new gene still had a novel, albeit weak, catalytic capacity. This is seen as a good example of how mutations easily can provide the raw material for evolution by natural selection.[18][19][20][21]

A 1995 paper showed that scientists have also been able to induce another species of bacterium, Pseudomonas aeruginosa, to evolve the capability to break down the same nylon byproducts in a laboratory by forcing them to live in an environment with no other source of nutrients.[22]

See also

[edit]

References

[edit]
  1. ^ a b Takehara, I; Kato, DI; Takeo, M; Negoro, S (27 April 2017). "Draft Genome Sequence of the Nylon Oligomer-Degrading Bacterium Arthrobacter sp. Strain KI72". Genome Announcements. 5 (17). doi:10.1128/genomeA.00217-17. PMC 5408104. PMID 28450506.
  2. ^ Takehara, I; Fujii, T; Tanimoto, Y (Jan 2018). "Metabolic pathway of 6-aminohexanoate in the nylon oligomer-degrading bacterium Arthrobacter sp. KI72: identification of the enzymes responsible for the conversion of 6-aminohexanoate to adipate". Applied Microbiology and Biotechnology. 102 (2): 801–814. doi:10.1007/s00253-017-8657-y. PMID 29188330. S2CID 20206702.
  3. ^ Michael Le Page (March 2009). "Five classic examples of gene evolution". New Scientist.
  4. ^ Kinoshita, S.; Kageyama, S.; Iba, K.; Yamada, Y.; Okada, H. (1975). "Utilization of a cyclic dimer and linear oligomers of e-aminocaproic acid by Achromobacter guttatus KI 72". Agricultural and Biological Chemistry. 39 (6): 1219–23. doi:10.1271/bbb1961.39.1219. ISSN 0002-1369.
  5. ^ S, Kinoshita; S, Negoro; M, Muramatsu; Vs, Bisaria; S, Sawada; H, Okada (1977-11-01). "6-Aminohexanoic Acid Cyclic Dimer Hydrolase. A New Cyclic Amide Hydrolase Produced by Achromobacter Guttatus KI74". European Journal of Biochemistry. 80 (2): 489–95. doi:10.1111/j.1432-1033.1977.tb11904.x. PMID 923591.
  6. ^ Negoro, S; Shinagawa, H; Nakata, A; Kinoshita, S; Hatozaki, T; Okada, H (July 1980). "Plasmid control of 6-aminohexanoic acid cyclic dimer degradation enzymes of Flavobacterium sp. KI72". Journal of Bacteriology. 143 (1): 238–45. doi:10.1128/JB.143.1.238-245.1980. PMC 294219. PMID 7400094.
  7. ^ "GTDB - GCF_002049485.1". Genome Taxonomy Database, revision 95. 2020.
  8. ^ Negoro, S; Kakudo, S; Urabe, I; Okada, H (1992). "A new nylon oligomer degradation gene (nylC) on plasmid pOAD2 from a Flavobacterium sp". Journal of Bacteriology. 174 (24): 7948–7953. doi:10.1128/jb.174.24.7948-7953.1992. PMC 207530. PMID 1459943.
  9. ^ a b Negoro S, Ohki T, Shibata N, et al. (June 2007). "Nylon-oligomer degrading enzyme/substrate complex: catalytic mechanism of 6-aminohexanoate-dimer hydrolase". J. Mol. Biol. 370 (1): 142–56. doi:10.1016/j.jmb.2007.04.043. PMID 17512009.
  10. ^ Negoro S, Taniguchi T, Kanaoka M, Kimura H, Okada H (July 1983). "Plasmid-determined enzymatic degradation of nylon oligomers". J. Bacteriol. 155 (1): 22–31. doi:10.1128/JB.155.1.22-31.1983. PMC 217646. PMID 6305910.
  11. ^ Yasuhira, K; Shibata, N; Mongami, G; Uedo, Y; Atsumi, Y; Kawashima, Y; Hibino, A; Tanaka, Y; Lee, YH; Kato, D; Takeo, M; Higuchi, Y; Negoro, S (8 January 2010). "X-ray crystallographic analysis of the 6-aminohexanoate cyclic dimer hydrolase: catalytic mechanism and evolution of an enzyme responsible for nylon-6 byproduct degradation". The Journal of Biological Chemistry. 285 (2): 1239–48. doi:10.1074/jbc.M109.041285. PMC 2801252. PMID 19889645.
  12. ^ Okada, H.; Negoro, S.; Kimura, H.; Nakamura, S. (10–16 November 1983). "Evolutionary adaptation of plasmid-encoded enzymes for degrading nylon oligomers". Nature. 306 (5939): 203–206. Bibcode:1983Natur.306..203O. doi:10.1038/306203a0. ISSN 0028-0836. PMID 6646204. S2CID 4364682.
  13. ^ a b Negoro, S; Shibata, N; Lee, YH; Takehara, I; Kinugasa, R; Nagai, K; Tanaka, Y; Kato, DI; Takeo, M; Goto, Y; Higuchi, Y (27 June 2018). "Structural basis of the correct subunit assembly, aggregation, and intracellular degradation of nylon hydrolase". Scientific Reports. 8 (1): 9725. Bibcode:2018NatSR...8.9725N. doi:10.1038/s41598-018-27860-w. PMC 6021441. PMID 29950566.
  14. ^ "Q57326". InterPro.
  15. ^ "MEROPS - the Peptidase Database".
  16. ^ Ohno S (April 1984). "Birth of a unique enzyme from an alternative reading frame of the preexisted, internally repetitious coding sequence". Proc Natl Acad Sci USA. 81 (8): 2421–5. Bibcode:1984PNAS...81.2421O. doi:10.1073/pnas.81.8.2421. PMC 345072. PMID 6585807.
  17. ^ Ohno, S (April 1984). "Birth of a unique enzyme from an alternative reading frame of the preexisted, internally repetitious coding sequence". Proceedings of the National Academy of Sciences. 81 (8): 2421–2425. Bibcode:1984PNAS...81.2421O. doi:10.1073/pnas.81.8.2421. ISSN 0027-8424. PMC 345072. PMID 6585807.
  18. ^ Thwaites WM (Summer 1985). "New Proteins Without God's Help". Creation Evolution Journal. 5 (2): 1–3.
  19. ^ "Evolution and Information: The Nylon Bug". New Mexicans for Science Education. Retrieved 2023-09-27.
  20. ^ Than, Ker (2005-09-23). "Why scientists dismiss 'intelligent design'". NBC News. Retrieved 2023-09-27.
  21. ^ Miller, Kenneth R. Only a Theory: Evolution and the Battle for America's Soul (2008) pp. 80-82
  22. ^ Prijambada ID, Negoro S, Yomo T, Urabe I (May 1995). "Emergence of nylon oligomer degradation enzymes in Pseudomonas aeruginosa PAO through experimental evolution". Appl. Environ. Microbiol. 61 (5): 2020–2. Bibcode:1995ApEnM..61.2020P. doi:10.1128/AEM.61.5.2020-2022.1995. PMC 167468. PMID 7646041.
[edit]