Part of the ecpRABCDE operon, which encodes the E.coli common pilus (ECP). ECP is found in both commensal and pathogenic strains and plays a dual role in early-stage biofilm development and host cell recognition. Positively regulates the expression of the ecp operon (By similarity). Negatively regulated by H-NS. Positively autoregulated. Also positively regulated by IHF (By similarity). Belongs to the EcpR/MatA family.