S-adenosylmethionine synthetase from Escherichia coli. Crystallization and preliminary X-ray diffraction studies.

摘要: S-Adenosylmethionine synthetase from Escherichia coli can be crystallized by the method of vapor diffusion using ammonium sulfate as precipitant. Two several crystal forms tetrameric (Mr = 180,000) enzyme have been examined x-ray diffraction methods. One form, a hexagonal bipyramid, develops when Mg2+ and PPi are added to protein solution. The space group is P62(22) or P64(22) with b 128.8 A, c 140.0 one subunit in asymmetric unit. other, regular octrahedron, addition 5% (v/v) 2-methyl-2,4-pentanediol. It P41(2)1(2) P4(3)2(1)2, 121.8 172.6 two subunits