This entry describes the C-terminal S1 domain found in type 2 RNase exonucleases. DrR63 proteins from Deinococcus radiodurans are an RNase II-type enzymes (DrII). Structure analysis of DrII indicates that it has an N-terminal HTH domain which interacts with a flexible loop that connects two beta-strands from the conserved C-terminal S1 domain, forming a beta-wing fold common in wHTH domains [1].

1: The structure and enzymatic properties of a novel RNase II family enzyme from Deinococcus radiodurans. Schmier BJ, Seetharaman J, Deutscher MP, Hunt JF, Malhotra A; J Mol Biol. 2012;415:547-559. PMID:22133431