Biochemistry 6th Edition by Reginald Garrett,Charles Grisham

Exercise 26

Exploring the Conformational Transitions of an Ion Transport Enzyme Structures of intermediate states of the sarcoplasmic reticulum Ca 2+ -ATPase have begun to reveal the conformation changes that convert ATP hydrolysis free energy into transport of Ca 2+ ions from the cytosol to the SR lumen. Consult the following reference and describe the details of "piston movement" by a critical transmembrane ? -helix in the transport cycle of this ion pump. (Kanai, R., ogwa. H. Vilsen, B., et al., 2013. Crystal structure of a Na + -bound Na + , K + -ATPase preceding the EIP state. Nature 502 :201-207; Moller, J.V., Olesen, C., Winther, A.-M., and Nissen, P., 2010. The sarcoplasmic Ca 2+ -ATPase: design of a perfect chemi-osmotic pump. Quarterly Review of Biophysics 43 :501-566.)