Requirement of domain-domain interaction for conformational change and functional ATP hydrolysis in myosin

Kohji Ito, Taro Q.P. Uyeda, Yoshikazu Suzuki, Kazuo Sutoh, Keiichi Yamamoto

Research output: Contribution to journalArticlepeer-review

28 Citations (Scopus)

Abstract

Coordination between the nucleotide-binding site and the converter domain of myosin is essential for its ATP-dependent motor activities. To unveil the communication pathway between these two sites, we investigated contact between side chains of Phe-482 in the relay helix and Gly-680 in the SH1-SH2 helix. F482A myosin, in which Phe-482 was changed to alanine with a smaller side chain, was not functional in vivo. In vitro, F482A myosin did not move actin filaments and the Mg2+Mg-ATPase activity of F482A myosin was hardly activated by actin. Phosphate burst and tryptophan fluorescence analyses, as well as fluorescence resonance energy transfer measurements to estimate the movements of the lever arm domain, indicated that the transition from the open state to the closed state, which precedes ATP hydrolysis, is very slow. In contrast, F482A/G680F doubly mutated myosin was functional in vivo and in vitro. The fact that a larger side chain at the 680th position suppresses the defects of F482A myosin suggests that the defects are caused by insufficient contact between side chains of Ala-482 and Gly-680. Thus, the contact between these two side chains appears to play an important role in the coordinated conformational changes and subsequent ATP hydrolysis.

Original languageEnglish
Pages (from-to)31049-31057
Number of pages9
JournalJournal of Biological Chemistry
Volume278
Issue number33
DOIs
Publication statusPublished - 2003 Aug 15

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

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