Role of Insert-1 of Myosin Vi in Modulating Nucleotide Affinity.
Pylypenko, O., Song, L., Squires, G., Liu, X., Zong, A.B., Houdusse, A., Sweeney, H.L.(2011) J Biol Chem 286: 11716
- PubMed: 21278381 
- DOI: https://doi.org/10.1074/jbc.M110.200626
- Primary Citation of Related Structures:  
2X51 - PubMed Abstract: 
Myosin VI is unique in its directionality among myosin superfamily members and also displays a slow and strain-dependent rate of ATP binding that allows for gating between its heads. In this study we demonstrate that leucine 310 is positioned by a class VI-specific insert, insert-1, so as to account for the selective hindrance of ATP versus ADP binding. Mutation of leucine 310 to glycine removes all influence of insert-1 on ATP binding. Furthermore, by analyzing myosin VI structures with either leucine 310 substituted to a glycine or complete removal of insert-1, we conclude that nucleotides may initially bind to myosin by their purine rings before docking their phosphate moieties. Otherwise, insert-1 could not exert a differential influence on ATP versus ADP binding.
Organizational Affiliation: 
Structural Motility, Institut Curie CNRS, UMR144, Paris, France.