Alternative N-terminal regions of <i>Drosophila</i> myosin heavy chain II regulate communication of the purine binding loop with the essential light chain.

ABSTRACT: We investigated the biochemical and biophysical properties of one of the four alternative exon-encoded regions within the Drosophila myosin catalytic domain. This region is encoded by alternative exons 3a and 3b and includes part of the N-terminal β-barrel. Chimeric myosin constructs (IFI-3a and EMB-3b) were generated by exchanging the exon 3-encoded areas between native slow embryonic body wall (EMB) and fast indirect flight muscle myosin isoforms (IFI). We found that this exchange alters the kinetic properties of the myosin S1 head. The ADP release rate (k_-D ) in the absence of actin is completely reversed for each chimera compared with the native isoforms. Steady-state data also suggest a reciprocal shift, with basal and actin-activated ATPase activity of IFI-3a

SUBMITTER: Bloemink MJ 

PROVIDER: S-EPMC7573276 | biostudies-literature | 2020 Oct

REPOSITORIES: biostudies-literature