This family consists of several bacterial FlaF flagellar proteins. FlaF and FlaG are trans-acting, regulatory factors that modulate flagellin synthesis during flagellum biogenesis [1].

1: Nucleotide sequence of the Caulobacter crescentus flaF and flbT genes and an analysis of codon usage in organisms with G + C-rich genomes. Schoenlein PV, Gallman LS, Winkler ME, Ely B; Gene 1990;93:17-25. PMID:1699845