HMM Summary Page: TIGR00830

FunctionPTS system, glucose subfamily, IIA component
Gene SymbolptbA
Trusted Cutoff97.50
Domain Trusted Cutoff97.50
Noise Cutoff78.75
Domain Noise Cutoff78.75
Isology Typesubfamily_domain
HMM Length121
Mainrole CategoryTransport and binding proteins
Subrole CategoryCarbohydrates, organic alcohols, and acids
AuthorPaulsen IT, Saier MH, Loftus BJ
Entry DateJul 25 2000 6:19PM
Last ModifiedFeb 14 2011 3:27PM
CommentThese are part of the The PTS Glucose-Glucoside (Glc) SuperFamily. The Glc family includes permeases specific for glucose, N-acetylglucosamine and a large variety of a- and b-glucosides. However, not all b-glucoside PTS permeases are in this class, as the cellobiose (Cel) b-glucoside PTS permease is in the Lac family (TC #4.A.3). The IIA, IIB and IIC domains of all of the permeases listed below are demonstrably homologous. These permeases show limited sequence similarity with members of the Fru family (TC #4.A.2). Several of the PTS permeases in the Glc family lack their own IIA domains and instead use the glucose IIA protein (IIAglc or Crr). Most of these permeases have the B and C domains linked together in a single polypeptide chain, and a cysteyl residue in the IIB domain is phosphorylated by direct phosphoryl transfer from IIAglc(his~P). Those permeases which lack a IIA domain include the maltose (Mal), arbutin-salicin-cellobiose (ASC), trehalose (Tre), putative glucoside (Glv) and sucrose (Scr) permeases of E. coli . Most, but not all Scr permeases of other bacteria also lack a IIA domain. The three-dimensional structures of the IIA and IIB domains of the E. coli glucose permease have been elucidated. IIAglchas a complex b-sandwich structure while IIBglc is a split ab-sandwich with a topology unrelated to the split ab-sandwich structure of HPr.
ReferencesA2 hmmalign SE ipaulsen AL clustalw_manual
Genome PropertyGenProp0119: PTS transport system (HMM)