Download MendeleyCrystal structure of calsequestrin from rabbit skeletal muscle sarcoplasmic reticulum.
Wang, S., Trumble, W.R., Liao, H., Wesson, C.R., Dunker, A.K., Kang, C.H.(1998) Nat Struct Biol 5: 476-483
- PubMed: 9628486
- DOI: https://doi.org/10.1038/nsb0698-476
- Primary Citation of Related Structures:
1A8Y - PubMed Abstract:
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.
Organizational Affiliation:
Department of Biochemistry and Biophysics, Washington State University, Pullman 99164-4660, USA.
