This family consists of uncharacterized proteins around 220 residues in length and is mainly found in various Streptococcus species. The function of this family is involved in acid resistance [1,2].

1: Streptococcus mutans ffh, a gene encoding a homologue of the 54 kDa subunit of the signal recognition particle, is involved in resistance to acid stress. Gutierrez,J.A., Crowley,P.J., Cvitkovitch,D.G., Brady,L.J., Hamilton,I.R., Hillman,J.D. and Bleiweis,A.S.; Microbiology 145 (Pt 2), 357-366 (1999). PMID:10075418

2: Characterization of the sat operon in Streptococcus mutans: evidence for a role of Ffh in acid tolerance. Kremer,B.H., van der Kraan,M., Crowley,P.J., Hamilton,I.R., Brady,L.J. and Bleiweis,A.S.; J. Bacteriol. 183 (8), 2543-2552 (2001) PMID:11274114