The Relay/Converter Interface Influences Hydrolysis of ATP by Skeletal Muscle Myosin II.

Bloemink, Marieke J. and Melkani, Girish C. and Bernstein, Sanford I. and Geeves, Michael A. (2015) The Relay/Converter Interface Influences Hydrolysis of ATP by Skeletal Muscle Myosin II. Journal of Biological Chemistry, 291 (4). pp. 1763-1773. ISSN 0021-9258. E-ISSN 1083-351X. (doi:https://doi.org/10.1074/jbc.M115.688002) (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)

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Official URL
http://doi.org/10.1074/jbc.M115.688002

Abstract

The interface between relay and converter domain of muscle myosin is critical for optimal myosin performance. Using Drosophila melanogaster indirect flight muscle S1, we performed a kinetic analysis of the effect of mutations in the converter and relay domain. Introduction of a mutation (R759E) in the converter domain inhibits the steady-state ATPase of myosin S1, whereas an additional mutation in the relay domain (N509K) is able to restore the ATPase toward wild-type values. The R759E S1 construct showed little effect on most steps of the actomyosin ATPase cycle. The exception was a 25–30% reduction in the rate constant of the hydrolysis step, the step coupled to the cross-bridge recovery stroke that involves a change in conformation at the relay/converter domain interface. Significantly, the double mutant restored the hydrolysis step to values similar to the wild-type myosin. Modeling the relay/converter interface suggests a possible interaction between converter residue 759 and relay residue 509 in the actin-detached conformation, which is lost in R759E but is restored in N509K/R759E. This detailed kinetic analysis of Drosophila myosin carrying the R759E mutation shows that the interface between the relay loop and converter domain is important for fine-tuning myosin kinetics, in particular ATP binding and hydrolysis.

Item Type: Article
Uncontrolled keywords: actin; fluorescence; homology modeling; kinetics; muscle; myosin; protein structure-function; sequence alignment
Subjects: Q Science
Divisions: Faculties > Sciences > School of Biosciences
Depositing User: Sue Davies
Date Deposited: 16 Feb 2016 14:52 UTC
Last Modified: 17 Feb 2016 09:27 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/54218 (The current URI for this page, for reference purposes)
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