Component of a type I toxin-antitoxin (TA) system (Probable). Either this protein or sequences upstream of it are required for translation of downstream flmA; this could be translationally coupled to flmA (PubMed:3049248). Part of the flmC-flmA operon; the antisense antitoxin RNA flmB of this system overlaps the ribosome-binding site and first 3 codons of this gene on the opposite strand. A plasmid unable to express the start codon of this protein can be lost without detriment to the bacteria, when normally the plasmid is not lost due to the Flm plasmid maintenance system.