3hsm | pdb_00003hsm
Crystal structure of distal N-terminal beta-trefoil domain of Ryanodine Receptor type 1
Structural highlights
FunctionRYR1_RABIT Calcium channel that mediates the release of Ca(2+) from the sarcoplasmic reticulum into the cytoplasm and thereby plays a key role in triggering muscle contraction following depolarization of T-tubules. Repeated very high-level exercise increases the open probability of the channel and leads to Ca(2+) leaking into the cytoplasm. Can also mediate the release of Ca(2+) from intracellular stores in neurons, and may thereby promote prolonged Ca(2+) signaling in the brain. Required for normal embryonic development of muscle fibers and skeletal muscle. Required for normal heart morphogenesis, skin development and ossification during embryogenesis (By similarity).[1] [2] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedMuscle contraction and relaxation is regulated by transient elevations of myoplasmic Ca(2+). Ca(2+) is released from stores in the lumen of the sarco(endo)plasmic reticulum (SER) to initiate formation of the Ca(2+) transient by activation of a class of Ca(2+) release channels referred to as ryanodine receptors (RyRs) and is pumped back into the SER lumen by Ca(2+)-ATPases (SERCAs) to terminate the Ca(2+) transient. Mutations in the type 1 ryanodine receptor gene, RYR1, are associated with 2 skeletal muscle disorders, malignant hyperthermia (MH), and central core disease (CCD). The evaluation of proposed mechanisms by which RyR1 mutations cause MH and CCD is hindered by the lack of high-resolution structural information. Here, we report the crystal structure of the N-terminal 210 residues of RyR1 (RyR(NTD)) at 2.5 A. The RyR(NTD) structure is similar to that of the suppressor domain of type 1 inositol 1,4,5-trisphosphate receptor (IP(3)Rsup), but lacks most of the long helix-turn-helix segment of the "arm" domain in IP(3)Rsup. The N-terminal beta-trefoil fold, found in both RyR and IP(3)R, is likely to play a critical role in regulatory mechanisms in this channel family. A disease-associated mutation "hot spot" loop was identified between strands 8 and 9 in a highly basic region of RyR1. Biophysical studies showed that 3 MH-associated mutations (C36R, R164C, and R178C) do not adversely affect the global stability or fold of RyR(NTD), supporting previously described mechanisms whereby mutations perturb protein-protein interactions. Crystal structure of type I ryanodine receptor amino-terminal beta-trefoil domain reveals a disease-associated mutation "hot spot" loop.,Amador FJ, Liu S, Ishiyama N, Plevin MJ, Wilson A, MacLennan DH, Ikura M Proc Natl Acad Sci U S A. 2009 Jul 7;106(27):11040-4. Epub 2009 Jun 18. PMID:19541610[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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