2ba0
Archaeal exosome coreArchaeal exosome core
Structural highlights
Function[RRP4_ARCFU] Non-catalytic component of the exosome, which is a complex involved in RNA degradation. Increases the RNA binding and the efficiency of RNA degradation. Confers strong poly(A) specificity to the exosome (Probable).[1] [2] [ECX2_ARCFU] Probably involved in the 3'->5' degradation of a variety of RNA species (Potential). [ECX1_ARCFU] Probably involved in the 3'->5' degradation of a variety of RNA species (Potential). 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 PubMedExosomes emerge as central 3'-->5' RNA processing and degradation machineries in eukaryotes and archaea. We determined crystal structures of two 230 kDa nine subunit archaeal exosome isoforms. Both exosome isoforms contain a hexameric ring of RNase phosphorolytic (PH) domain subunits with a central chamber. Tungstate soaks identified three phosphorolytic active sites in this processing chamber. A trimer of Csl4 or Rrp4 subunits forms a multidomain macromolecular interaction surface on the RNase-PH domain ring with central S1 domains and peripheral KH and zinc-ribbon domains. Structural and mutational analyses suggest that the S1 domains and a subsequent neck in the RNase-PH domain ring form an RNA entry pore to the processing chamber that only allows access of unstructured RNA. This structural framework can mechanistically unify observed features of exosomes, including processive degradation of unstructured RNA, the requirement for regulatory factors to degrade structured RNA, and left-over tails in rRNA trimming. Structural framework for the mechanism of archaeal exosomes in RNA processing.,Buttner K, Wenig K, Hopfner KP Mol Cell. 2005 Nov 11;20(3):461-71. PMID:16285927[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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