The structure of the rigor complex and its implications for the power stroke

Decorated actin provides a model system for studying the strong interaction between actin and myosin. Cryo-energy-filter electron microscopy has recently yielded a 14 Å resolution map of rabbit skeletal actin decorated with chicken skeletal S1. The crystal structure of the cross-bridge from skeletal...

Full description

Saved in:
Bibliographic Details
Published in:Philosophical transactions of the Royal Society of London. Series B. Biological sciences 2004-12, Vol.359 (1452), p.1819-1828
Main Authors: Holmes, K. C., Trentham, D. R., Simmons, R., Schröder, R. R., Sweeney, H. L., Houdusse, Anne
Format: Article
Language:English
Subjects:
Actin
Actins
Actins - physiology
Animals
Arm
Biomechanical Phenomena
Coordinate systems
Cryo-Energy-Filter Electron Microscopy
Crystal structure
Decorated Actin
Electron microscopy
Microfilaments
Models, Biological
Models, Molecular
Muscle Contraction - physiology
Muscle, Skeletal - physiology
Myosin Cross-Bridge
Myosin V
Myosins - physiology
Nucleotides
Protein Conformation
Rotation
Smooth muscle
Strong Binding
Switches
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Decorated actin provides a model system for studying the strong interaction between actin and myosin. Cryo-energy-filter electron microscopy has recently yielded a 14 Å resolution map of rabbit skeletal actin decorated with chicken skeletal S1. The crystal structure of the cross-bridge from skeletal chicken myosin could not be fitted into the three-dimensional electron microscope map without some deformation. However, a newly published structure of the nucleotide-free myosin V cross-bridge, which is apparently already in the strong binding form, can be fitted into the three-dimensional reconstruction without distortion. This supports the notion that nucleotide-free myosin V is an excellent model for strongly bound myosin and allows us to describe the actin-myosin interface. In myosin V the switch 2 element is closed although the lever arm is down (post-power stroke). Therefore, it appears likely that switch 2 does not open very much during the power stroke. The myosin V structure also differs from the chicken skeletal myosin structure in the nucleotide-binding site and the degree of bending of the backbone ß-sheet. These suggest a mechanism for the control of the power stroke by strong actin binding.
ISSN:0962-8436
1471-2970
DOI:10.1098/rstb.2004.1566