An unexpectedly large working stroke from chymotryptic fragments of myosin II

FEBS Letters

Kendrick-Jones, J.²  Tregear, R.T.²  Veigel, C.¹  Molloy, J.E.¹ 

[1] Department of Biology, University of York, York Y01 5DW, UK;MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, UK

关键词: Myosin;    Working stroke;    Optical trap;    Motor;    Muscle;    Single molecule;    MD;    motor domain;    LCD;    light chain binding domain;    S-1;    subfragment 1;    the digestion product containing the motor head of myosin;    S-1(A1);    S-1(A2);    the chymotryptically derived motor head isoenzymes;    ELC;    essential light chain;    RLC;    regulatory light chain;   

DOI  :  10.1016/S0014-5793(00)01937-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

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.

【 授权许可】

Unknown