Weak and Strong States of Kinesin and ncd

@article{citeulike:2588745, abstract = {Kinesin superfamily molecular motors step along microtubules (MTs)viaa cycle of conformational changes which is coupled to ATP turnover. To probe the coupling mechanism, we titrated the effects of various nucleotides on MT binding by two superfamily members; MT plus-end-directed kinesin and MT minus-end-directed non claret disjunctional (ncd). For both motors, the nucleotide-free state induced by apyrase was the strongest binding (Kkind~0.003 [mu]M,Kncdd~0.24 [mu]M), whilst the ADP state was the weakest binding (Kkind~11.32 [mu]M,Kncdd~12.02 [mu]M). In ATP, the motor.ADP state dominates and the binding is accordingly ADP-like, but in the presence of the slowly hydrolysed analogue adenosine 5'-O-(3-thiotriphosphate) there is a shift towards tighter binding (Kkind~4.23 [mu]M,Kncdd~2.34 [mu]M), consistent with a tight-binding motor.ATP-like state being enriched. In the presence of non-hydrolysable analogue [beta],[gamma]- imidoadenosine 5'-triphosphate the binding is still tighter (Kkind~<0.27 [mu]M,Kncdd~0.21 [mu]M), close to the values obtained with apyrase. For both kinesin and ncd, ADP has the unique quality that it traps the motor in a weak binding state. MT tight binding catalyses escape from this state, changing the active site conformation such that both ADP release and ADP binding are accelerated. The data are consistent with a simple two-state scheme in which both kinesin and ncd switch from weak to strong bindingviaADP release, and back againviaADP trapping. In a two-state model, the transition from weak to strong binding is force-generating.}, author = {Crevel, Isabelle M. and Lockhart, Andrew and Cross, Robert A. }, citeulike-article-id = {2588745}, doi = {10.1006/jmbi.1996.0147}, journal = {Journal of Molecular Biology}, keywords = {binding, experiment, kinesin, kinetics, microtubule}, month = {March}, number = {1}, pages = {66--76}, posted-at = {2008-03-26 08:32:54}, priority = {2}, title = {Weak and Strong States of Kinesin and ncd}, url = {http://dx.doi.org/10.1006/jmbi.1996.0147}, volume = {257}, year = {1996} }

TY - JOUR ID - citeulike:2588745 L3 - citeulike-article-id:2588745 TI - Weak and Strong States of Kinesin and ncd JF - Journal of Molecular Biology VL - 257 IS - 1 SP - 66 EP - 76 N2 - Kinesin superfamily molecular motors step along microtubules (MTs)viaa cycle of conformational changes which is coupled to ATP turnover. To probe the coupling mechanism, we titrated the effects of various nucleotides on MT binding by two superfamily members; MT plus-end-directed kinesin and MT minus-end-directed non claret disjunctional (ncd). For both motors, the nucleotide-free state induced by apyrase was the strongest binding (Kkind~0.003 [mu]M,Kncdd~0.24 [mu]M), whilst the ADP state was the weakest binding (Kkind~11.32 [mu]M,Kncdd~12.02 [mu]M). In ATP, the motor.ADP state dominates and the binding is accordingly ADP-like, but in the presence of the slowly hydrolysed analogue adenosine 5'-O-(3-thiotriphosphate) there is a shift towards tighter binding (Kkind~4.23 [mu]M,Kncdd~2.34 [mu]M), consistent with a tight-binding motor.ATP-like state being enriched. In the presence of non-hydrolysable analogue [beta],[gamma]- imidoadenosine 5'-triphosphate the binding is still tighter (Kkind~<0.27 [mu]M,Kncdd~0.21 [mu]M), close to the values obtained with apyrase. For both kinesin and ncd, ADP has the unique quality that it traps the motor in a weak binding state. MT tight binding catalyses escape from this state, changing the active site conformation such that both ADP release and ADP binding are accelerated. The data are consistent with a simple two-state scheme in which both kinesin and ncd switch from weak to strong bindingviaADP release, and back againviaADP trapping. In a two-state model, the transition from weak to strong binding is force-generating. KW - binding KW - experiment KW - kinesin KW - kinetics KW - microtubule AU - Crevel, Isabelle AU - Lockhart, Andrew AU - Cross, Robert PY - 1996/03/22/ UR - http://dx.doi.org/10.1006/jmbi.1996.0147 ER -