2p51 | pdb_00002p51
Crystal structure of the S. pombe Pop2p deadenylation subunit
Structural highlights
Function[CAF1_SCHPO] Acts as the catalytic component of the CCR4-NOT core complex, which in the nucleus seems to be a general transcription factor, and in the cytoplasm the major mRNA deadenylase involved in mRNA turnover. In vivo and in vitro, caf1 has 3'-exoribonuclease activity with a preference for poly(A) RNAs.[1] [2] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedDeadenylation is the first and probably also rate-limiting step of controlled mRNA decay in eukaryotes and therefore central for the overall rate of gene expression. In yeast, the process is maintained by the mega-Dalton Ccr4-Not complex, of which both the Ccr4p and Pop2p subunits are 3'-5' exonucleases potentially responsible for the deadenylation reaction. Here, we present the crystal structure of the Pop2p subunit from Schizosaccharomyces pombe determined to 1.4 A resolution and show that the enzyme is a competent ribonuclease with a tunable specificity towards poly-A. In contrast to S. cerevisiae Pop2p, the S. pombe enzyme contains a fully conserved DEDDh active site, and the high resolution allows for a detailed analysis of its configuration, including divalent metal ion binding. Functional data further indicates that the identity of the ions in the active site can modulate both activity and specificity of the enzyme, and finally structural superposition of single nucleotides and poly-A oligonucleotides provide insight into the catalytic cycle of the protein. The 1.4-A crystal structure of the S. pombe Pop2p deadenylase subunit unveils the configuration of an active enzyme.,Jonstrup AT, Andersen KR, Van LB, Brodersen DE Nucleic Acids Res. 2007;35(9):3153-64. Epub 2007 Apr 22. PMID:17452359[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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