2BA1

Archaeal exosome core

Summary for 2BA1

• Entry DOI: 10.2210/pdb2ba1/pdb
• Related: 2BA0
• Descriptor: Archaeal exosome RNA binding protein CSL4, Archaeal exosome complex exonuclease RRP41, Archaeal exosome complex exonuclease RRP42, ... (5 entities in total)
• Functional Keywords: exosome, rnase ph, rna degradation, exoribonuclease, rna binding, s1 domain, zn-ribbon, archaeal, phosphorolytic, rna binding protein
• Biological source: Archaeoglobus fulgidus; More
• Cellular location: Cytoplasm : O30033 O29757 O29756
• Total number of polymer chains: 9
• Total formula weight: 231770.91

Authors

Hopfner, K.P.,Buttner, K.,Wenig, K. (deposition date: 2005-10-13, release date: 2005-11-22, Last modification date: 2024-02-14)

Primary citation

Buttner, K.,Wenig, K.,Hopfner, K.P.
Structural framework for the mechanism of archaeal exosomes in RNA processing.
Mol.Cell, 20:461-471, 2005

PubMed Abstract: Exosomes 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.

PubMed: 16285927
DOI: 10.1016/j.molcel.2005.10.018

Experimental method

X-RAY DIFFRACTION (2.7 Å)