2.A.14 The Lactate Permease (LctP) Family
Proteins of the LctP family have been found in Gram-negative and Gram-positive bacteria as well as archaea. One member of the family, from E. coli, is the lactate:H+ symporter (Dong et al., 1993). Two closely related paralogues have been found encoded within the E. coli genome, and one of these has been shown to be the glycolate uptake permease (Nunez et al., 2001). Both permeases transport the same acids (L- and D-lactate as well as glycolate), but their physiological substrates differ. The lactate permease transports both L- and D-lactate while the glycolate permease transports glycolate under physiological conditions. Regulatory effects determine the substrates transported in vivo.
Transport reactions catalyzed by functionally characterized members of the LctP family include:
D- or L-lactate or glycolate (out) + H+ (out) → D- or L-lactate or glycolate (in) + H+ (in).
This family belongs to the IT Superfamily.
|Dong, J.M., J.S. Taylor, D.J. Latour, S. Iuchi, and E.C.C. Lin. (1993). Three overlapping lct genes involved in L-lactate utilization by Escherichia coli. J. Bacteriol. 175: 6671-6678.|
|Garai, P., A. Lahiri, D. Ghosh, J. Chatterjee, and D. Chakravortty. (2015). Peptide utilizing carbon starvation gene yjiY is required for flagella mediated infection caused by Salmonella. Microbiology. [Epub: Ahead of Print]|
|Moraes, T.F. and R.A. Reithmeier. (2012). Membrane transport metabolons. Biochim. Biophys. Acta. 1818: 2687-2706.|
|Nunez, M.F., M.T. Pellicer, J. Badia, J. Aguilar, and L. Baldoma. (2001). The gene yghK linked to the glc operon of Escherichia coli encodes a permease for glycolate that is structurally and functionally similar to L-lactate permease. Microbiology 147: 1069-1077.|
|Núñez, M.F., O. Kwon, T.H. Wilson, J. Aguilar, L. Baldoma, and E.C. Lin. (2002). Transport of L-Lactate, D-Lactate, and glycolate by the LldP and GlcA membrane carriers of Escherichia coli. Biochem. Biophys. Res. Commun. 290: 824-829.|
|Rabus, R, D.L. Jack, D.J. Kelly, and M.H. Saier, Jr. (1999). TRAP transporters: an ancient family of extracytoplasmic solute-receptor-dependent secondary active transporters. Microbiology 145: 3431-3445.|
|Saier, M.H., Jr., B.H. Eng, S. Fard, J. Garg, D.A. Haggerty, W.J. Hutchinson, D.L. Jack, E.C. Lai, H.J. Liu, D.P. Nusinew, A.M. Omar, S.S. Pao, I.T. Paulsen, J.A. Quan, M. Sliwinski, T.T. Tseng, S. Wachi, and G.B. Young. (1999). Phylogenetic characterization of novel transport protein families revealed by genome analyses. Biochim. Biophys. Acta 1422: 1-56.|
Lactate permease, LctP or LidP (substrates: L-lactate, D-lactate and glycolate) (Núñez et al. 2002).
LctP (LldP) of E. coli
Glycolate permease, GlcA or YghK (substrates: L-lactate, D-lactate and glycolate).
Encoded in an operon with malate synthase and glycolate oxidase (Moraes and Reithmeier 2012).
GlcA or YghK of E. coli
|2.A.14.1.3||L-lactate permease||Bacilli||LutP of Bacillus subtilis |
|2.A.14.1.4||Putative transporter||Archaea||Putative transporter of Methanopyrus kandleri (gi 20095088)|
|2.A.14.2.1||Unknown permease ||Archaea ||LctP homologue of Sulfolobus solfataricus |