Novel cryo-EM structure of an ADP-bound GroEL-GroES complex

Sci Rep. 2021 Sep 14;11(1):18241. doi: 10.1038/s41598-021-97657-x.

Abstract

The GroEL-GroES chaperonin complex is a bacterial protein folding system, functioning in an ATP-dependent manner. Upon ATP binding and hydrolysis, it undergoes multiple stages linked to substrate protein binding, folding and release. Structural methods helped to reveal several conformational states and provide more information about the chaperonin functional cycle. Here, using cryo-EM we resolved two nucleotide-bound structures of the bullet-shaped GroEL-GroES1 complex at 3.4 Å resolution. The main difference between them is the relative orientation of their apical domains. Both structures contain nucleotides in cis and trans GroEL rings; in contrast to previously reported bullet-shaped complexes where nucleotides were only present in the cis ring. Our results suggest that the bound nucleotides correspond to ADP, and that such a state appears at low ATP:ADP ratios.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Diphosphate / chemistry*
  • Adenosine Diphosphate / metabolism
  • Binding Sites
  • Chaperonin 10 / chemistry*
  • Chaperonin 10 / metabolism
  • Chaperonin 60 / chemistry*
  • Chaperonin 60 / metabolism
  • Cryoelectron Microscopy
  • Escherichia coli Proteins / chemistry*
  • Escherichia coli Proteins / metabolism
  • Protein Binding

Substances

  • Chaperonin 10
  • Chaperonin 60
  • Escherichia coli Proteins
  • Adenosine Diphosphate