Expression, purification, crystallization and preliminary X-ray crystallographic analysis of human myosin 1c in complex with calmodulin

Myosin 1c (Myo1c) is implicated in several cellular processes such as vesicle transport and the mediation of adaptation in the inner ear. Consequently, mutations impairing Myo1c motor activity lead to hearing loss in humans. To understand the role of Myo1c in this process on a molecular level, its crystal structure in complex with the light chain calmodulin was determined. A human Myo1c construct encompassing the motor domain and the first IQ motif was co-expressed with calmodulin in Sf9 cells and purified to homogeneity. The protein complex crystallized readily, and the crystals belonged to space group P2₁ and diffracted to 3 Å resolution. Attempts to determine the structure by molecular replacement are currently under way.