X-ray structure and activity of the yeast Pop2 protein: a nuclease subunit of the mRNA deadenylase complex.
In Saccharomyces cerevisiae, a large complex, known as the Ccr4-Not complex, containing two nucleases, is responsible for mRNA deadenylation. One of these nucleases is called Pop2 and has been identified by similarity with PARN, a human poly(A) nuclease. Here, we present the crystal structure of the nuclease domain of Pop2 at 2.3 A resolution. The domain has the fold of the DnaQ family and represents the first structure of an RNase from the DEDD superfamily. Despite the presence of two non-canonical residues in the active site, the domain displays RNase activity on a broad range of RNA substrates. Site-directed mutagenesis of active-site residues demonstrates the intrinsic ability of the Pop2 RNase D domain to digest RNA. This first structure of a nuclease involved in the 3'-5' deadenylation of mRNA in yeast provides information for the understanding of the mechanism by which the Ccr4-Not complex achieves its functions.
Thore
Stéphane
S
European Molecular Biology Laboratory, Meyerhofstrasse 1, D-69117 Heidelberg, Germany.
Mauxion
Fabienne
F
Séraphin
Bertrand
B
Suck
Dietrich
D
D000595:Amino Acid Sequence; D001665:Binding Sites; D018360:Crystallography, X-Ray; D004268:DNA-Binding Proteins / Q000737:chemistry; D053418:Death Domain Receptor Signaling Adaptor Proteins; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011061:Poly A / Q000235:genetics; D011131:Polyribonucleotides / Q000235:genetics; D011506:Proteins / Q000737:chemistry* / Q000235:genetics; D012260:Ribonucleases / Q000737:chemistry / Q000378:metabolism*; D012441:Saccharomyces cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D016415:Sequence Alignment; D014157:Transcription Factors; D015003:Yeasts / Q000201:enzymology* / Q000235:genetics
C489780:CNOT8 protein, human; C116096:DEDD protein, human; D004268:DNA-Binding Proteins; D053418:Death Domain Receptor Signaling Adaptor Proteins; D047908:Intracellular Signaling Peptides and Proteins; D011131:Polyribonucleotides; D011506:Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D011061:Poly A; C078657:CCR4 protein, S cerevisiae; D012260:Ribonucleases; C445084:mRNA deadenylase; C079009:POP2 protein, S cerevisiae