5oql

Cryo-EM structure of the 90S pre-ribosome from Chaetomium thermophilumCryo-EM structure of the 90S pre-ribosome from Chaetomium thermophilum

5oql, resolution 3.20Å Show:Asymmetric Unit Biological Assembly Structural highlights 5oql is a 10 chain structure with sequence from Chaetomium thermophilum var. thermophilum DSM 1495. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: Electron Microscopy, Resolution 3.2Å Ligands: Experimental data: Check Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function G0SF93_CHATD Publication Abstract from PubMed The 40S small ribosomal subunit is cotranscriptionally assembled in the nucleolus as part of a large chaperone complex called the 90S preribosome or small-subunit processome. Here, we present the 3.2-A-resolution structure of the Chaetomium thermophilum 90S preribosome, which allowed us to build atomic structures for 34 assembly factors, including the Mpp10 complex, Bms1, Utp14 and Utp18, and the complete U3 small nucleolar ribonucleoprotein. Moreover, we visualized the U3 RNA heteroduplexes with a 5' external transcribed spacer (5' ETS) and pre-18S RNA, and their stabilization by 90S factors. Overall, the structure explains how a highly intertwined network of assembly factors and pre-rRNA guide the sequential, independent folding of the individual pre-40S domains while the RNA regions forming the 40S active sites are kept immature. Finally, by identifying the unprocessed A1 cleavage site and the nearby Utp24 endonuclease, we suggest a proofreading model for regulated 5'-ETS separation and 90S-pre-40S transition. 3.2-A-resolution structure of the 90S preribosome before A1 pre-rRNA cleavage.,Cheng J, Kellner N, Berninghausen O, Hurt E, Beckmann R Nat Struct Mol Biol. 2017 Oct 2. doi: 10.1038/nsmb.3476. PMID:28967883 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Ribosome 3D structures