Biology:Gluconate-proton symporter

From HandWiki
Gluconate:H+ Symporter
Identifiers
SymbolGntP
PfamPF02447
InterProIPR003474

The gluconate:H+ symporter (GntP) family (TC# 2.A.8) is a family of transport proteins belonging to the ion transporter (IT) superfamily.[1] Members of the GntP family include known gluconate permeases of E. coli and Bacillus species such as the D-Gluconate:H+ symporter of Bacillus subtillus (GntP; TC# 2.A.8.1.1) and the D-fructuronate/D-gluconate:H+ symporter of E. coli (GntP; TC# 2.A.8.1.3).[2][3][4] A representative list of proteins belonging to the GntP family can be found in the Transporter Classification Database.[5]

Structure

Bioinformatic analysis suggests these proteins are of about 450 residues and possess 12 or 14 putative transmembrane α-helical spanners. No crystal structure data are available for GntP proteins as of early 2016.

Function

Four of the seven E. coli paralogues have been found to possess active gluconate uptake activity, and one of them (GntW; TC# 2.A.8.1.2) can accommodate both L-idonate and D-gluconate, although L-idonate is the physiological substrate. Another (GntP) transports D-gluconate with high affinity but is specifically induced by and transports D-fructuronate.[4] GntT of E. coli is the physiological gluconate permease.[6]

Transport reaction

The generalized transport reaction catalyzed by proteins of the GntP family is:

Carbohydrate acid (out) + nH+ (out) → Carbohydrate acid (in) + nH+ (in)

References

  1. "The ion transporter superfamily". Biochimica et Biophysica Acta (BBA) - Biomembranes 1618 (1): 79–92. December 2003. doi:10.1016/j.bbamem.2003.10.010. PMID 14643936. 
  2. "Characterization of a novel transporter family that includes multiple Escherichia coli gluconate transporters and their homologues". FEMS Microbiology Letters 147 (2): 233–8. February 1997. doi:10.1016/s0378-1097(96)00532-0. PMID 9119199. 
  3. "Analysis of the gluconate (gnt) operon of Bacillus subtilis". Molecular Microbiology 5 (5): 1081–9. May 1991. doi:10.1111/j.1365-2958.1991.tb01880.x. PMID 1659648. 
  4. 4.0 4.1 "GntP is the Escherichia coli Fructuronic acid transporter and belongs to the UxuR regulon". Journal of Bacteriology 186 (22): 7690–6. November 2004. doi:10.1128/JB.186.22.7690-7696.2004. PMID 15516583. 
  5. "2.A.8 The Gluconate:H+ Symporter (GntP) Family". http://www.tcdb.org/search/result.php?tc=2.A.8. 
  6. "Molecular genetic characterization of the Escherichia coli gntT gene of GntI, the main system for gluconate metabolism". Journal of Bacteriology 179 (5): 1584–90. March 1997. doi:10.1128/jb.179.5.1584-1590.1997. PMID 9045817.