How Ca2+-ATPase pumps ions across the sarcoplasmic reticulum membrane.
Ca2+-ATPase of muscle sarcoplasmic reticulum is an ATP-powered Ca2+-pump that establishes a >10,000 fold concentration gradient across the membrane. Its crystal structures have been determined for 9 different states that cover nearly the entire reaction cycle. Presented here is a brief structural account of the ion pumping process, with emphasis on why the structure has to be so.
Toyoshima
Chikashi
C
Institute of Molecular and Cellular Biosciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan. ct@iam.u-tokyo.ac.jp
D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D001665:Binding Sites; D002118:Calcium / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism*; D008958:Models, Molecular; D017434:Protein Structure, Tertiary; D012519:Sarcoplasmic Reticulum / Q000378:metabolism* / Q000648:ultrastructure; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
C032197:beta-aspartyl phosphate; D001224:Aspartic Acid; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D002118:Calcium