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Publication Abstract from PubMed

Myosins are molecular motors that power diverse cellular processes, such as rapid organelle transport, muscle contraction, and tension-sensitive anchoring. The structural adaptations in the motor that allow for this functional diversity are not known, due, in part, to the lack of high-resolution structures of highly tension-sensitive myosins. We determined a 2.3-A resolution structure of apo-myosin-Ib (Myo1b), which is the most tension-sensitive myosin characterized. We identified a striking unique orientation of structural elements that position the motor's lever arm. This orientation results in a cavity between the motor and lever arm that holds a 10-residue stretch of N-terminal amino acids, a region that is divergent among myosins. Single-molecule and biochemical analyses show that the N terminus plays an important role in stabilizing the post power-stroke conformation of Myo1b and in tuning the rate of the force-sensitive transition. We propose that this region plays a general role in tuning the mechanochemical properties of myosins.

A vertebrate myosin-I structure reveals unique insights into myosin mechanochemical tuning.,Shuman H, Greenberg MJ, Zwolak A, Lin T, Sindelar CV, Dominguez R, Ostap EM Proc Natl Acad Sci U S A. 2014 Feb 11;111(6):2116-21. doi:, 10.1073/pnas.1321022111. Epub 2014 Jan 27. PMID:24469830^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.