1a8y
CRYSTAL STRUCTURE OF CALSEQUESTRIN FROM RABBIT SKELETAL MUSCLE SARCOPLASMIC RETICULUM AT 2.4 A RESOLUTION
|
OverviewOverview
Calsequestrin, the major Ca2+ storage protein of muscle, coordinately, binds and releases 40-50 Ca2+ ions per molecule for each, contraction-relaxation cycle by an uncertain mechanism. We have determined, the structure of rabbit skeletal muscle calsequestrin. Three very negative, thioredoxin-like domains surround a hydrophilic center. Each monomer makes, two extensive dimerization contacts, both of which involve the approach of, many negative groups. This structure suggests a mechanism by which, calsequestrin may achieve high capacity Ca2+ binding. The suggested, mechanism involves Ca2+-induced collapse of the three domains and, polymerization of calsequestrin monomers arising from three factors:, N-terminal arm exchange, helix-helix contacts and Ca2+ cross bridges. This, proposed structure-based mechanism accounts for the observed coupling of, high capacity Ca2+ binding with protein precipitation.
About this StructureAbout this Structure
1A8Y is a Single protein structure of sequence from Oryctolagus cuniculus. Full crystallographic information is available from OCA.
ReferenceReference
Crystal structure of calsequestrin from rabbit skeletal muscle sarcoplasmic reticulum., Wang S, Trumble WR, Liao H, Wesson CR, Dunker AK, Kang CH, Nat Struct Biol. 1998 Jun;5(6):476-83. PMID:9628486
Page seeded by OCA on Tue Nov 20 10:41:17 2007