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An unexpectedly large working stroke from chymotryptic fragments of myosin II
Author(s) -
Molloy J.E.,
Kendrick-Jones J.,
Veigel C.,
Tregear R.T.
Publication year - 2000
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(00)01937-2
Subject(s) - myosin , myosin head , actin , molecular motor , biophysics , stroke (engine) , rotation (mathematics) , skeletal muscle , chemistry , myosin light chain kinase , neuroscience , anatomy , biology , physics , biochemistry , computer science , artificial intelligence , thermodynamics
Recent structural evidence indicates that the light chain domain of the myosin head (LCD) bends on the motor domain (MD) to move actin. Structural models usually assume that the actin‐MD interface remains static and the possibility that part of the myosin working stroke might be produced by rotation about the acto‐myosin interface has been neglected. We have used an optical trap to measure the movement produced by proteolytically shortened single rabbit skeletal muscle myosin heads (S‐1(A1) and S‐1(A2)). The working stroke produced by these shortened heads was more than that which the MD‐LCD bend mechanism predicts from the full‐length (papain) S‐1's working stroke obtained under similar conditions. This result indicates that part of the working stroke may be caused by motor action at the actin‐MD interface.