RRP40 is a non-catalytic component of the RNA exosome complex which has 3'->5' exoribonuclease activity and participates in a multitude of cellular RNA processing and degradation events. It consists of a N-terminal beta-sandwich hybrid domain (Pfam:PF21261), a central S1 domain and a C-terminal KH domain (Pfam:PF15985). This entry represents the S1 RNA binding domain, which has an OB fold [1-3].

1: The exosome contains domains with specific endoribonuclease, exoribonuclease and cytoplasmic mRNA decay activities. Schaeffer D, Tsanova B, Barbas A, Reis FP, Dastidar EG, Sanchez-Rotunno M, Arraiano CM, van Hoof A; Nat Struct Mol Biol. 2009;16:56-62. PMID:19060898

2: Distinct and evolutionary conserved structural features of the human nuclear exosome complex. Gerlach P, Schuller JM, Bonneau F, Basquin J, Reichelt P, Falk S, Conti E; Elife. 2018; [Epub ahead of print] PMID:30047866

3: RNA degradation paths in a 12-subunit nuclear exosome complex. Makino DL, Schuch B, Stegmann E, Baumgartner M, Basquin C, Conti E; Nature. 2015;524:54-58. PMID:26222026