HMM Summary Page: TIGR00823

FunctionPTS system, lactose-specific IIa component
Gene SymbollacF
Trusted Cutoff136.95
Domain Trusted Cutoff136.95
Noise Cutoff117.85
Domain Noise Cutoff117.85
Isology Typesubfamily
EC Number2.7.1.69
HMM Length99
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
CommentThe PTS Lactose-N,N?-Diacetylchitobiose-b-glucoside (Lac) Family (TC 4.A.3) Bacterial PTS transporters transport and concomitantly phosphorylate their sugar substrates, and typically consist of multiple subunits or protein domains. The Lac family includes several sequenced lactose (b-galactoside) permeases of Gram-positive bacteria as well as the E. coli N,N?-diacetylchitobiose (Chb) permease which can transport aromatic b-glucosides and cellobiose as well as the chitin disaccharide, Chb, but only Chb induces expression of the chb operon. While the Lac permeases consist of two polypeptide chains (IIA and IICB), the Chb permease of E. coli consists of three (IIA, IIB and IIC). In B. subtilis, a PTS permease similar to the Chb permease of E. coli is believed to transport lichenan (a b-1,3;1,4 glucan) degradation products, oligosaccharides of 2-4 glucose units. This Hmm is specific for the IIA subunit of the Lac PTS family.
ReferencesA2 hmmalign SE ipaulsen AL clustalw_manual