InterPro domain: IPR004879

Members of this family are highly conserved proteins present in eukaryotes, bacteria and archaea, about 600-800 amino acids in length, which contain a TRX domain with a redox active CXXC motif. The human/rat protein, called SSP411, is specifically expressed in the testis in an age-dependent manner. The SSP411 mRNA is increased during spermiogenesis and is localized in round and elongated spermatids, suggesting a function in fertility regulation [ 1 ].

1. Cloning and characterization of rat spermatid protein SSP411: a thioredoxin-like protein. J. Androl. 25, 479-93