Regulates secA expression by translational coupling of the secM secA operon. Translational pausing at a specific Pro residue 5 residues before the end of the protein may allow disruption of a mRNA repressor helix that normally suppresses secA translation initiation. The active form is cytosolic, while the periplasmic form is rapidly degraded, mainly by the tail-specific protease. Belongs to the SecM family.