This family of proteins is encoded by the dual function SR1 RNA. SR1 is a sRNA which regulates arginine metabolism [1], it also encodes a short protein that binds to glyceraldehyde-3-phosphate dehydrogenase (GapA) and stabilises the gapA operon mRNAs [2].

1: The small untranslated RNA SR1 from the Bacillus subtilis genome is involved in the regulation of arginine catabolism. Heidrich N, Chinali A, Gerth U, Brantl S; Mol Microbiol. 2006;62:520-536. PMID:17020585

2: A dual-function sRNA from B. subtilis: SR1 acts as a peptide encoding mRNA on the gapA operon. Gimpel M, Heidrich N, Mader U, Krugel H, Brantl S; Mol Microbiol. 2010;76:990-1009. PMID:20444087