Gp23.1 from Bacillus subtilis SPP1 phage adopts a hexamer assembly and is likely to function as a chaperone [1]. This family of highly conserved sequences is predominantly found in phages with long non-contractile tails and in bacterial prophages.

1: Crystal structure of Bacillus subtilis SPP1 phage gp23.1, a putative chaperone. Veesler D, Blangy S, Lichiere J, Ortiz-Lombardia M, Tavares P, Campanacci V, Cambillau C; Protein Sci. 2010;19:1812-1816. PMID:20665904