HMM Summary Page: TIGR03025

Functionexopolysaccharide biosynthesis polyprenyl glycosylphosphotransferase
Trusted Cutoff295.55
Domain Trusted Cutoff295.55
Noise Cutoff292.45
Domain Noise Cutoff292.45
Isology Typesubfamily
HMM Length445
AuthorSelengut J
Entry DateJul 28 2006 11:03AM
Last ModifiedFeb 14 2011 3:27PM
CommentMembers 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.
ReferencesRN [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.
Genome PropertyGenProp0912: Leptospira exopolysaccharide biosynthesis clusters (HMM)