Competence protein ComF (IPR005222)

Short name: Competence_ComF

Overlapping homologous superfamilies

Family relationships



Competence is the ability of a cell to take up exogenous DNA from its environment, resulting in transformation. It is widespread among bacteria and is probably an important mechanism for the horizontal transfer of genes. DNA usually becomes available by the death and lysis of other cells. Competent bacteria use components of extracellular filaments called type 4 pili to create pores in their membranes and pull DNA through the pores into the cytoplasm. This process, including the development of competence and the expression of the uptake machinery, is regulated in response to cell-cell signalling and/or nutritional conditions [PMID: 8901420].

The development of genetic competence in Bacillus subtilis is a highly regulated adaptive response to stationary-phase stress. For competence to develop, the transcriptional regulator, ComK, must be activated. ComK is required for the expression of genes encoding proteins that function in DNA uptake. In log-phase cultures, ComK is inactive in a complex with MecA and ClpC. The comS gene is induced in response to high culture cell density and nutritional stress and its product functions to release active ComK from the complex. ComK then stimulates the transcription initiation of its own gene as well as that of the late competence operons [PMID: 10361283].

Proteins in this family are found in bacterial species which posses systems for natural transformation (competence) (eg Bacillus subtilis, Haemophilus influenzae), and also species without these systems (eg Escherichia coli). Competence protein F has been shown to be important for the uptake of exogenous DNA in naturally competent bacteria, though the precise role of this protein is not yet known [PMID: 1577704, PMID: 8412657]. GntX is a periplasmic gluconate binding protein thought to be part of a high-affinity gluconate transport system [PMID: 9871335].

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.