Response regulator in the two-component regulatory system ComP/ComA involved in a major quorum response pathway that regulates the development of genetic competence. Regulates directly the expression of over 20 genes, including genes of the srfA operon, degQ, rapA, rapC, rapE, rapF, etc. Regulates indirectly, through the regulation of comK transcription, the expression of late competence genes. Phosphorylated by ComP.