| Comment | Members of this family are generally found near other genes involved in the biosynthesis of a variety of exopolysaccharides. These proteins consist of two fused domains, an N-terminal hydrophobic domain of generally low conservation and a highly conserved C-terminal sugar transferase domain (PF02397). Characterized and partially characterized members of this subfamily include Salmonella WbaP (originally RfbP) [1], E. coli WcaJ [2], Methylobacillus EpsB [3], Xanthomonas GumD [4], Vibrio CpsA [5], Erwinia AmsG [6], Group B Streptococcus CpsE (originally CpsD) [7], and Streptococcus suis Cps2E [8]. Each of these is believed to act in transferring the sugar from, for instance, UDP-glucose or UDP-galactose, to a lipid carrier such as undecaprenyl phosphate as the first (priming) step in the synthesis of an oligosaccharide "block". This function is encoded in the C-terminal domain. The liposaccharide is believed to be subsequently transferred through a "flippase" function from the cytoplasmic to the periplasmic face of the inner membrane by the N-terminal domain.
Certain closely related transferase enzymes such as Sinorhizobium ExoY [9] and Lactococcus EpsD [10] lack the N-terminal domain and are not found by this model. |
| References | RN [1]
RM PMID: 8626328
RT C-terminal half of Salmonella enterica WbaP (RfbP) is the galactosyl-1-phosphate transferase domain catalyzing the first step of O-antigen synthesis.
RA Wang L, Liu D, Reeves PR
RL J Bacteriol. 1996 May;178(9):2598-604.
RN [2]
RM PMID: 318640
RT Role of a sugar-lipid intermediate in colanic acid synthesis by Escherichia coli.
RA Johnson JG, Wilson DB
RL J Bacteriol. 1977 Jan;129(1):225-36.
RN [3]
RM 12624205
RA Yoshida T, Ayabe Y, Yasunaga M, Usami Y, Habe H, Nojiri H, Omori T
RT Genes involved in the synthesis of the exopolysaccharide methanolan by the obligate methylotroph Methylobacillus sp strain 12S.
RL Microbiology. 2003 Feb;149(Pt 2):431-44.
RN [4]
RM PMID: 9537354
RT Xanthomonas campestris pv. campestris gum mutants: effects on xanthan biosynthesis and plant virulence.
RA Katzen F, Ferreiro DU, Oddo CG, Ielmini MV, Becker A, Puhler A, Ielpi L
RL J Bacteriol. 1998 Apr;180(7):1607-17.
RN [5]
RM PMID: 12949095
RT Multiple regulators control capsular polysaccharide production in Vibrio parahaemolyticus.
RA Guvener ZT, McCarter LL
RL J Bacteriol. 2003 Sep;185(18):5431-41.
RN [6]
RM PMID: 7596293
RT Molecular analysis of the ams operon required for exopolysaccharide synthesis of Erwinia amylovora.
RA Bugert P, Geider K
RL Mol Microbiol. 1995 Mar;15(5):917-33.
RN [7]
RM PMID: 8355611
RT Identification of cpsD, a gene essential for type III capsule expression in group B streptococci.
RA Rubens CE, Heggen LM, Haft RF, Wessels MR
RL Mol Microbiol. 1993 May;8(5):843-55.
RN [8]
RM PMID: 10085014
RT Identification and characterization of the cps locus of Streptococcus suis serotype 2: the capsule protects against phagocytosis and is an important virulence factor.
RA Smith HE, Damman M, van der Velde J, Wagenaar F, Wisselink HJ, Stockhofe-Zurwieden N, Smits MA
RL Infect Immun. 1999 Apr;67(4):1750-6.
RN [9]
RM PMID: 14769477
RT The key Sinorhizobium meliloti succinoglycan biosynthesis gene exoY is expressed from two promoters.
RA Cheng HP, Yao SY
RL FEMS Microbiol Lett. 2004 Feb 9;231(1):131-6.
RN [10]
RM PMID: 10515924
RT Functional analysis of glycosyltransferase genes from Lactococcus lactis and other gram-positive cocci: complementation, expression, and diversity.
RA van Kranenburg R, Vos HR, van Swam II, Kleerebezem M, de Vos WM
RL J Bacteriol. 1999 Oct;181(20):6347-53. |
