Protein Family Models

TraF protein undergoes proteolytic processing associated with export. The 19 amino acids at the amino terminus of the polypeptides appear to constitute a typical membrane leader peptide - not included in this family, while the remainder of the molecule is predicted to be primarily hydrophilic in character [1]. F plasmid TraF and TraH are required for F pilus assembly and F plasmid transfer, and they are both localised to the outer membrane in the presence of the complete F transfer region, especially TraV, the putative anchor [2]. [1]. 3042757. The product of the F plasmid transfer operon gene, traF, is a periplasmic protein. Wu JH, Kathir P, Ippen-Ihler K;. J Bacteriol. 1988;170:3633-3639. [2]. 20081027. F plasmid TraF and TraH are components of an outer membrane complex involved in conjugation. Arutyunov D, Arenson B, Manchak J, Frost LS;. J Bacteriol. 2010;192:1730-1734. (from Pfam)

Gene:

traF

Date:

2024-10-16

type-F conjugative transfer system pilin assembly protein TraF is localized to the outer membrane or the periplasmic side of the cytoplasmic membrane and has protease activity; as a member of the S26 family of signal peptidases it catalyzes an initial step in the export of the broad-host-range plasmid RP4 pilus subunit

Date:

2017-12-04

This protein is part of a large group of proteins involved in conjugative transfer of plasmid DNA, specifically the F-type system. This protein has been predicted to contain a thioredoxin fold and has been shown to be localized to the periplasm [1]. Unlike the related protein TrbB (TIGR02738), TraF does not contain a conserved pair of cysteines and has been shown not to function as a thiol disulfide isomerase by complementation of an Ecoli DsbA defect [2]. The protein is believed to be involved in pilin assembly [3]. Even more closely related than TrbB is a clade of genes (TIGR02740) which do contain the CXXC motif, but it is unclear whether these genes are involved in type-F conjugation systems per se.

Gene:

traF

Date:

2019-09-10

Date:

2020-10-26