Crystallization and preliminary X-ray crystallographic studies of the D2 region of the skeletal muscle ryanodine receptor

The N-terminal portion (amino acids 1303-1367) of the type 1 ryanodine rece ptor D2 region is thought to be critical for excitation-contraction couplin g in skeletal muscle. A segment of the D2 region (amino acids 1317-1355) wa s expressed as a glutathione S-transferase fusion protein (GST-D2) and then crystallized at room temperature using ammonium sulfate as precipitant. Us ing a newly developed cryo-soaking method, complete native data sets were m easured to a resolution of 2.2 Angstrom using synchrotron radiation. The cr ystal was found to be hexagonal, belonging to space group P6(3)22, with uni t-cell parameters a = b = 116.1, c = 77.9 Angstrom.