6HDD

OBP chaperonin in the nucleotide-free state

Summary for 6HDD

• Entry DOI: 10.2210/pdb6hdd/pdb
• EMDB information: 0191 0204
• Descriptor: Putative chaperonin GroEL (1 entity in total)
• Functional Keywords: chaperonin, nucleotide-free, chaperone
• Biological source: Pseudomonas phage OBP
• Total number of polymer chains: 7
• Total formula weight: 400817.92

Authors

Semenyuk, P.I.,Stanishneva-Konovalova, T.B.,Sokolova, O.S. (deposition date: 2018-08-17, release date: 2019-08-28, Last modification date: 2024-05-15)

Primary citation

Stanishneva-Konovalova, T.B.,Semenyuk, P.I.,Kurochkina, L.P.,Pichkur, E.B.,Vasilyev, A.L.,Kovalchuk, M.V.,Kirpichnikov, M.P.,Sokolova, O.S.
Cryo-EM reveals an asymmetry in a novel single-ring viral chaperonin.
J.Struct.Biol., 209:107439-107439, 2020

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 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.

PubMed: 31870903
DOI: 10.1016/j.jsb.2019.107439

Experimental method

ELECTRON MICROSCOPY (4.5 Å)