HMM Summary Page: TIGR02804

FunctionTonB system transport protein ExbD
Gene SymbolexpD
Trusted Cutoff123.45
Domain Trusted Cutoff123.45
Noise Cutoff86.35
Domain Noise Cutoff86.35
Isology Typeequivalog
HMM Length121
Gene Ontology TermGO:0006810: transport biological_process
GO:0015570: energizer of outer membrane receptor-mediated transport activity molecular_function
AuthorHaft DH
Entry DateJan 24 2006 10:54AM
Last ModifiedFeb 14 2011 3:27PM
CommentMembers of this family are Gram-negative bacterial inner membrane proteins, generally designated ExbD, related to the TolR family modeled by TIGRFAMs TIGR02801. Members always are encoded next to a protein designated ExbB (TIGR02797), related to the TolQ family modeled by TIGRFAMs TIGR02796. ExbD and ExbB together form a proton channel through which they can harness the proton-motive force to energize TonB, which in turn energizes TonB-dependent receptors in the outer membrane. TonB-dependent receptors with known specificity tend to import siderophores or vitamin B12. A TonB system and Tol-Pal system often will co-exist in a single bacterial genome.
Genome PropertyGenProp0543: TonB-dependent transport (HMM)