Cryo-EM reveals different coronin binding modes for ADP- and ADP-BeFx actin filaments

Nat Struct Mol Biol. 2014 Dec;21(12):1075-81. doi: 10.1038/nsmb.2907. Epub 2014 Nov 2.

Abstract

Essential cellular processes involving the actin cytoskeleton are regulated by auxiliary proteins that can sense the nucleotide state of actin. Here we report cryo-EM structures for ADP-bound and ADP-beryllium fluoride (ADP-BeFx, an ADP-Pi mimic)-bound actin filaments in complex with the β-propeller domain of yeast coronin 1 (crn1), at 8.6-Å resolution. Our structures reveal the main differences in the interaction of coronin with the two nucleotide states of F-actin. We derived pseudoatomic models by fitting the atomic structures of actin and coronin into the EM envelopes and confirmed the identified interfaces on actin by chemical cross-linking, fluorescence spectroscopy and actin mutagenesis. The models offer a structural explanation for the nucleotide-dependent effects of coronin on cofilin-assisted remodeling of F-actin.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actin Cytoskeleton / metabolism*
  • Actin Cytoskeleton / ultrastructure
  • Actins / metabolism*
  • Actins / ultrastructure
  • Adenosine Diphosphate / metabolism*
  • Amino Acid Sequence
  • Animals
  • Beryllium / metabolism
  • Cryoelectron Microscopy
  • Fluorides / metabolism
  • Microfilament Proteins / chemistry
  • Microfilament Proteins / metabolism*
  • Microfilament Proteins / ultrastructure
  • Models, Molecular
  • Protein Binding
  • Protein Structure, Tertiary
  • Rabbits
  • Saccharomyces cerevisiae / chemistry
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae / ultrastructure

Substances

  • Actins
  • Microfilament Proteins
  • coronin proteins
  • beryllium fluoride
  • Adenosine Diphosphate
  • Beryllium
  • Fluorides