Jump to content

NiCoT family: Difference between revisions

From Wikipedia, the free encyclopedia
Content deleted Content added
Created page with 'Proteins currently known to belong to the '''Ni<sup>2+</sup>-Co<sup>2+</sup> Transporter (NiCoT) Family''' ([http://www.tcdb.org/search/result.php?tc=2.A.52 TC#...'
 
mNo edit summary
Line 22: Line 22:
{{refend}}
{{refend}}


[[Category:Metal transporter]]
[[Category:Permeases]]
[[Category:Membrane proteins]]
[[Category:Membrane proteins]]
[[Category:Enzymes of known structure]]
[[Category:Enzymes of known structure]]

Revision as of 19:02, 5 January 2016

Proteins currently known to belong to the Ni2+-Co2+ Transporter (NiCoT) Family (TC# 2.A.52) can be found in organisms ranging from Gram-negative and Gram-positive bacteria to archaea and some eukaryotes. Members of this family catalyze uptake of Ni2+ and/or Co2+ in a proton motive force-dependent process. [1]

Structure

These proteins range in size from about 300 to 400 amino acyl residues and possess 7 or 8 transmembrane segments (TMSs) thought to result from intragenic 4 TMS duplication, followed by a deletion in the case of the 7 TMS variety. Topological analyses with the HoxN Ni2+ transporter of Ralstonia eutropha (Alcaligenes eutrophus) suggest that it possesses 8 TMSs with its N- and C-termini in the cytoplasm. The Co2+ (Ni2+) transporter of Rhodococcus rhodochrous, NhlF, exhibits eight putative TMSs, and eight apparent TMSs are revealed by a hydropathy analysis of the multiple alignment of the NiCoT family protein sequences. An HX4DH sequence in helix 2 of the HoxN protein has been implicated in Ni2+ binding, and both helix 1 and helix 2 which interact spatially, form the selectivity filter[2]. In the H. pylori NixA homologue, several conserved motifs have been shown to be important for Ni2+ binding and transport. [3][1]

At least one crystal structure is known, found by Yu et. al. [4], available at PDB: 4M58​.

Reaction

The overall reaction catalyzed by the proteins of the NiCoT family is: [1]

[Ni2+ and/or Co2+] (out) → [Ni2+ and/or Co2+] (in).

Proteins

Several known proteins belong to the Ni2+-Co2+ Transporter (NiCoT) Family. A complete list of these proteins along with their transporter classification identification number (TCID), domain, kingdom/phylum, and some examples can be found in the Transporter Classification Database.

References

  1. ^ a b c Saier, Milton. "Transporter Classification Database: 2.A.43 The Lysosomal Cystine Transporter (LCT) Family". tcdb.org. Retrieved 4 January 2016.
  2. ^ Degen, O; Eitinger, T (July 2002). "Substrate specificity of nickel/cobalt permeases: insights from mutants altered in transmembrane domains I and II". J Bacteriol. 184 (13): 3569–77. PMID 12057951.
  3. ^ Wolfram, L; Bauerfeind, P (March 2002). "Conserved low-affinity nickel-binding amino acids are essential for the function of the nickel permease NixA of Helicobacter pylori". J Bacteriol. 184 (5): 1438–43. PMID 11844775.
  4. ^ Yu, Y; Zhou, M; Kirsch, F; Xu, C; Zhang, L; Wang, Y; Jiang, Z; Wang, N; Li, J; Eitinger, T; Yang, M (December 24, 2013). "Planar substrate-binding site dictates the specificity of ECF-type nickel/cobalt transporters". Cell research. 24 (3): 267–277. doi:10.1038/cr.2013.172.

Further Reading