Calmodulin, S-100, and crayfish sarcoplasmic calcium-binding protein crystals suitable for X-ray diffraction studies.

We have grown crystals of calmodulin, of S-100, and crayfish sarcoplasmic calcium-binding protein and are now determining their structures by x-ray diffraction. The sarcoplasmic calcium-binding protein crystallizes from 50% 2-methyl-2,4-pentanediol in space group P2(1)2(1)2(1) with unit cell dimensions of 58.9, 68.

The molecular structure of yeast phenylalanine transfer RNA in monoclinic crystals.

The molecular structure of monoclinic crystals of yeast phenylalanine tRNA is analyzed by comparing it to the orthorhombic crystals of the same material whose structure has been determined. Changing the packing of the molecule from the head-to-head, tail-to-tail arrangement in the orthorhombic lattice to a head-to-tail packing makes it possible to generate a proposed structure for the monoclinic unit cell. The structure factors for the proposed arrangement have been calculated and compared with those experimentally observed from monoclinic crystals.