This domain is a receptor binding domain found on bacteriophage short tail fibre proteins. It contains a zinc-binding site and a potential lipopolysaccharide-binding site [1].

1: The structure of the receptor-binding domain of the bacteriophage T4 short tail fibre reveals a knitted trimeric metal-binding fold. Thomassen E, Gielen G, Schutz M, Schoehn G, Abrahams JP, Miller S, van Raaij MJ; J Mol Biol 2003;331:361-373. PMID:12888344