Domain structure of the myosin head in correlation-averaged images of shadowed molecules.
Electron microscope images of rotary shadowed myosin heads and subfragment-1 (S1) have been computationally aligned and averaged using correlation methods. Average images show reproducible detail within the 'pear-shaped' envelope of the head; the major features are invariant in S1 and in intact heads, in two mirror-related views of the head, and in the presence and absence of ATP. The averages support the view that the head contains two main structural domains separated by a cleft, and that the region of the neck close to the head-rod junction is flexible. They also reveal the inadequacy of the conventional method of correcting the measured dimensions of shadowed particles for the supposed thickness of the 'metal coat'.
Rosenstiel Basic Medical Sciences Research Center, Brandeis University, Waltham, Massachusetts 02254.
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PJ
Vibert
D000255:Adenosine Triphosphate / Q000378:metabolism; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008854:Microscopy, Electron; D009119:Muscle Contraction; D009126:Muscle Relaxation; D015879:Myosin Subfragments; D009218:Myosins / Q000378:metabolism; D010446:Peptide Fragments / Q000378:metabolism
D015879:Myosin Subfragments; D010446:Peptide Fragments; D000255:Adenosine Triphosphate; D009218:Myosins