HMM Summary Page: TIGR04361

Functionentry exclusion protein TrbK
Trusted Cutoff50.00
Domain Trusted Cutoff50.00
Noise Cutoff40.00
Domain Noise Cutoff40.00
Isology Typeequivalog
HMM Length64
AuthorHaft DH
Entry DateJul 20 2012 10:09AM
Last ModifiedJul 20 2012 10:20AM
CommentMembers of this family are encoded between the genes for TrbJ and TrbL of P-type plasmid conjugal transfer systems, and therefore are TrbK, a member of a guild of unrelated TrbK protein families. The similarly located TrbK of plasmid RP4 (family TIGR04359) functions in entry exclusion, and the current family may as well, despite lacking any detectable homology. Members of this family include TrbK of the Ti plasmid from Agrobacterium, shown not to be required for transfer, which would be consistent with a role in entry exclusion rather than transfer itself. Li et al. (PMID:10438776) cite unpublished results that showed an entry exclusion function for TrbK of the Ti plasmid. This small protein shares close C-terminal sequence homology to the much longer protein encoded by the neighboring gene TrbJ.
ReferencesRN [1] RM PMID:10438776 RT Essential components of the Ti plasmid trb system, a type IV macromolecular transporter. RA Li PL, Hwang I, Miyagi H, True H, Farrand SK RL J Bacteriol. 1999 Aug;181(16):5033-41.