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 (By similarity). Positively regulates the expression of the ecp operon by binding to two TTCCT boxes. Negatively regulated by H-NS. Positively autoregulated. Also positively regulated by IHF. Belongs to the EcpR/MatA family.