Competence, DNA-entry nuclease inhibitor, ComJ (IPR020354)

Short name: Competence_nuclease_inhibitor

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 proteins in this entry play a role in the competence of cells to be transformed. They inhibit the activity of the DNA-entry nuclease. DNA-entry nuclease inhibitor is a subunit of a 75 kDa protein complex, which governs binding and entry of donor DNA. The complex is a tetramer of two subunits of the DNA-entry nuclease and two subunits of a competence-specific protein ComJ. Only the complex is able to bind ds- and ss-DNA [PMID: 2841296]. It is found in the plasma membrane.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
  • PD081734 (DNA-entry_nuclease_inhibitor)