This family of bacterial proteins includes SPy_2034 from Streptococcus pyogenes, which is though to play an important role in the virulence of the bacteria. This protein shows a unique tetrameric organisation composed of four helix-loop- helix motifs [1].

1: Functional and structural properties of a novel protein and virulence factor (Protein sHIP) in Streptococcus pyogenes. Wisniewska M, Happonen L, Kahn F, Varjosalo M, Malmstrom L, Rosenberger G, Karlsson C, Cazzamali G, Pozdnyakova I, Frick IM, Bjorck L, Streicher W, Malmstrom J, Wikstrom M; J Biol Chem. 2014;289:18175-18188. PMID:24825900