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Load and Pi control flux through the branched kinetic cycle of myosin V

Kad, Neil M, Trybus, Kathleen M, Warshaw, David M (2008) Load and Pi control flux through the branched kinetic cycle of myosin V. The Journal of biological chemistry, 283 (25). pp. 17477-84. ISSN 0021-9258. E-ISSN 1083-351X. (doi:10.1074/jbc.M800539200) (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided) (KAR id:42947)

The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided.
Official URL:
http://dx.doi.org/10.1074/jbc.M800539200

Abstract

Myosin V is a processive actin-based motor protein that takes multiple 36-nm steps to deliver intracellular cargo to its destination. In the laser trap, applied load slows myosin V heavy meromyosin stepping and increases the probability of backsteps. In the presence of 40 mm phosphate (P(i)), both forward and backward steps become less load-dependent. From these data, we infer that P(i) release commits myosin V to undergo a highly load-dependent transition from a state in which ADP is bound to both heads and its lead head trapped in a pre-powerstroke conformation. Increasing the residence time in this state by applying load increases the probability of backstepping or detachment. The kinetics of detachment indicate that myosin V can detach from actin at two distinct points in the cycle, one of which is turned off by the presence of P(i). We propose a branched kinetic model to explain these data. Our model includes P(i) release prior to the most load-dependent step in the cycle, implying that P(i) release and load both act as checkpoints that control the flux through two parallel pathways.

Item Type: Article
DOI/Identification number: 10.1074/jbc.M800539200
Subjects: Q Science
Divisions: Divisions > Division of Natural Sciences > Biosciences
Depositing User: Neil Kad
Date Deposited: 15 Sep 2014 19:27 UTC
Last Modified: 16 Nov 2021 10:17 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/42947 (The current URI for this page, for reference purposes)

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