COLLEGE OF ARTS AND SCIENCES Department of Mathematics and Statistics

Seminars

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Special Applied Math Seminar: MOLECULAR DYNAMICS SIMULATIONS OF CONFORMATIONAL CHANGES IN MOTOR PROTEINS

2006-03-29

4:10 p.m. Neill Hall 3W

Ed Pate

Myosin is the motor protein that generates force and motion in muscles. Kinesin-family motors are involved in intracellular organelle movement and mitosis. Defining the atomic-level conformational changes that occur in motor proteins, and their relationship to the generation of force and motion is a fundamental goal of the motility field. One surprise that came from the x-ray crystallographic structures of myosin (an actin-based motor), and kinesin (a microtubule-based motor) was the significant structural homology between the two classes of proteins, suggesting a common evolutionary ancestor protein. One structural difference between the proteins is in the triphosphate-binding domain at the nucleotide site. In myosin x-ray structures, the motor protein is seen to interact closely with the nucleotide. In kinesin x-ray structures, the interaction is very weak due to a displacement of a portion of the protein away from the nucleotide. X-ray structures are static snapshots of the proteins in time and subsequent spectroscopic studies have suggested that distinct open and closed states may actually exist as part of both the myosin and kinesin motor cycles. I will discuss molecular dynamics modeling simulations of the nucleotide sites of the two classes of motor proteins as a mechanism for probing conformational changes at the nucleotide sites detected by spectroscopy and the implications on the mechanism for force generation by motor proteins