6C1H

High-Resolution Cryo-EM Structures of Actin-bound Myosin States Reveal the Mechanism of Myosin Force Sensing


Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 3.9 Å
  • Aggregation State: HELICAL ARRAY 
  • Reconstruction Method: HELICAL 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

High-resolution cryo-EM structures of actin-bound myosin states reveal the mechanism of myosin force sensing.

Mentes, A.Huehn, A.Liu, X.Zwolak, A.Dominguez, R.Shuman, H.Ostap, E.M.Sindelar, C.V.

(2018) Proc. Natl. Acad. Sci. U.S.A. --: --

  • DOI: 10.1073/pnas.1718316115
  • Primary Citation of Related Structures:  6C1D, 6C1G

  • PubMed Abstract: 
  • Myosins adjust their power outputs in response to mechanical loads in an isoform-dependent manner, resulting in their ability to dynamically adapt to a range of motile challenges. Here, we reveal the structural basis for force-sensing based on near-a ...

    Myosins adjust their power outputs in response to mechanical loads in an isoform-dependent manner, resulting in their ability to dynamically adapt to a range of motile challenges. Here, we reveal the structural basis for force-sensing based on near-atomic resolution structures of one rigor and two ADP-bound states of myosin-IB (myo1b) bound to actin, determined by cryo-electron microscopy. The two ADP-bound states are separated by a 25° rotation of the lever. The lever of the first ADP state is rotated toward the pointed end of the actin filament and forms a previously unidentified interface with the N-terminal subdomain, which constitutes the upper half of the nucleotide-binding cleft. This pointed-end orientation of the lever blocks ADP release by preventing the N-terminal subdomain from the pivoting required to open the nucleotide binding site, thus revealing how myo1b is inhibited by mechanical loads that restrain lever rotation. The lever of the second ADP state adopts a rigor-like orientation, stabilized by class-specific elements of myo1b. We identify a role for this conformation as an intermediate in the ADP release pathway. Moreover, comparison of our structures with other myosins reveals structural diversity in the actomyosin binding site, and we reveal the high-resolution structure of actin-bound phalloidin, a potent stabilizer of filamentous actin. These results provide a framework to understand the spectrum of force-sensing capacities among the myosin superfamily.


    Organizational Affiliation

    Pennsylvania Muscle Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Actin, alpha skeletal muscle
A, B, C, D, E
375Oryctolagus cuniculusGene Names: ACTA1 (ACTA)
Find proteins for P68135 (Oryctolagus cuniculus)
Go to Gene View: ACTA1
Go to UniProtKB:  P68135
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Unconventional myosin-Ib
P
729Rattus norvegicusGene Names: Myo1b (Myo1a, Myr1)
Find proteins for Q05096 (Rattus norvegicus)
Go to UniProtKB:  Q05096
Entity ID: 3
MoleculeChainsSequence LengthOrganismDetails
Calmodulin
R
148N/AN/A
Protein Feature View is not available: No corresponding UniProt sequence found.
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ADP
Query on ADP

Download SDF File 
Download CCD File 
A, B, C, D, E
ADENOSINE-5'-DIPHOSPHATE
C10 H15 N5 O10 P2
XTWYTFMLZFPYCI-KQYNXXCUSA-N
 Ligand Interaction
MG
Query on MG

Download SDF File 
Download CCD File 
A, B, C, D, E
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 3.9 Å
  • Aggregation State: HELICAL ARRAY 
  • Reconstruction Method: HELICAL 
Software Package:
Software NamePurpose
PHENIXrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History & Funding Information

Deposition Data


Funding OrganizationCountryGrant Number
National Institutes of Health/National Institute of General Medical SciencesUnited StatesR37 GM057247

Revision History 

  • Version 1.0: 2018-01-31
    Type: Initial release
  • Version 1.1: 2018-02-07
    Type: Database references