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Publication Abstract from PubMed

Despite extensive scrutiny of the myosin superfamily, the lack of high-resolution structures of actin-bound states has prevented a complete description of its mechanochemical cycle and limited insight into how sequence and structural diversification of the motor domain gives rise to specialized functional properties. Here we present cryo-EM structures of the unique minus-end directed myosin VI motor domain in rigor (4.6 A) and Mg-ADP (5.5 A) states bound to F-actin. Comparison to the myosin IIC-F-actin rigor complex reveals an almost complete lack of conservation of residues at the actin-myosin interface despite preservation of the primary sequence regions composing it, suggesting an evolutionary path for motor specialization. Additionally, analysis of the transition from ADP to rigor provides a structural rationale for force sensitivity in this step of the mechanochemical cycle. Finally, we observe reciprocal rearrangements in actin and myosin accompanying the transition between these states, supporting a role for actin structural plasticity during force generation by myosin VI.

Cryo-EM structures reveal specialization at the myosin VI-actin interface and a mechanism of force sensitivity.,Gurel PS, Kim LY, Ruijgrok PV, Omabegho T, Bryant Z, Alushin GM Elife. 2017 Dec 4;6. doi: 10.7554/eLife.31125. PMID:29199952^[1]

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