The R369 Myosin Residue within Loop 4 Is Critical for Actin Binding and Muscle Function in Drosophila.

ABSTRACT: The myosin molecular motor interacts with actin filaments in an ATP-dependent manner to yield muscle contraction. Myosin heavy chain residue R369 is located within loop 4 at the actin-tropomyosin interface of myosin's upper 50 kDa subdomain. To probe the importance of R369, we introduced a histidine mutation of that residue into Drosophila myosin and implemented an integrative approach to determine effects at the biochemical, cellular, and whole organism levels. Substituting the similarly charged but bulkier histidine residue reduces maximal actin binding in vitro without affecting myosin ATPase activity. R369H mutants exhibit impaired flight ability that is dominant in heterozygotes and progressive with age in homozygotes. Indirect flight muscle ultrastructure is normal in mutant h

SUBMITTER: Trujillo AS 

PROVIDER: S-EPMC8910226 | biostudies-literature | 2022 Feb

REPOSITORIES: biostudies-literature