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-Structure paper
Title | Cryo-EM reveals an asymmetry in a novel single-ring viral chaperonin. |
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Journal, issue, pages | J Struct Biol, Vol. 209, Issue 2, Page 107439, Year 2020 |
Publish date | Feb 1, 2020 |
Authors | Tatiana B Stanishneva-Konovalova / Pavel I Semenyuk / Lidia P Kurochkina / Evgeny B Pichkur / Alexander L Vasilyev / Mikhail V Kovalchuk / Mikhail P Kirpichnikov / Olga S Sokolova / |
PubMed Abstract | Chaperonins are ubiquitously present protein complexes, which assist the proper folding of newly synthesized proteins and prevent aggregation of denatured proteins in an ATP-dependent manner. They ...Chaperonins are ubiquitously present protein complexes, which assist the proper folding of newly synthesized proteins and prevent aggregation of denatured proteins in an ATP-dependent manner. They are classified into group I (bacterial, mitochondrial, chloroplast chaperonins) and group II (archaeal and eukaryotic cytosolic variants). However, both of these groups do not include recently discovered viral chaperonins. Here, we solved the symmetry-free cryo-EM structures of a single-ring chaperonin encoded by the gene 246 of bacteriophage OBP Pseudomonas fluorescens, in the nucleotide-free, ATPγS-, and ADP-bound states, with resolutions of 4.3 Å, 5.0 Å, and 6 Å, respectively. The structure of OBP chaperonin reveals a unique subunit arrangement, with three pairs of subunits and one unpaired subunit. Each pair combines subunits in two possible conformations, differing in nucleotide-binding affinity. The binding of nucleotides results in the increase of subunits' conformational variability. Due to its unique structural and functional features, OBP chaperonin can represent a new group. |
External links | J Struct Biol / PubMed:31870903 |
Methods | EM (single particle) |
Resolution | 4.5 - 6.5 Å |
Structure data | EMDB-0191: EMDB-0204, PDB-6hdd: EMDB-0208: |
Source |
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Keywords | CHAPERONE / chaperonin / nucleotide-free |