来自红螺菌的1,5-二磷酸核酮糖羧化酶/加氧酶的新晶体形式。

New crystal forms of ribulose-1,5-bisphosphate carboxylase/oxygenase from Rhodospirillum rubrum.

作者信息

Schneider G, Brändén C I, Lorimer G

出版信息

J Mol Biol. 1986 Jan 5;187(1):141-3. doi: 10.1016/0022-2836(86)90415-8.

Abstract

Three crystal forms of the dimeric form of the enzyme ribulose-1,5-bisphosphate carboxylase from the photosynthetic bacterium Rhodospirillum rubrum have been obtained from the gene product expressed in Escherichia coli. Form A crystals formed from the quaternary complex comprising enzyme-activator carbamate-Mg2+-2'-carboxyarabinitol-1,5-bisphosphate are shown here to be devoid of ligands. In contrast, crystals of the quaternary complex formed with the hexadecameric L8S8 enzyme from spinach contain both the activator carbamate and 2'-carboxyarabinitol-1,5-bisphosphate. Form B crystals of the R. rubrum enzyme are monoclinic, space group P2(1) with cell dimensions a = 65.5 A, b = 70.6 A, c = 104.1 A and beta = 92.1 degrees, with two subunits per asymmetric unit. Rotation function calculations show a non-crystallographic 2-fold axis perpendicular to the monoclinic b-axis. Form C crystals are orthorhombic (space group P2(1)2(1)2(1)) with cell dimensions a = 79.4 A, b = 100.1 A and c = 131.0 A. The monoclinic crystal form diffracts to at least 2.0 A resolution on a conventional X-ray source.

摘要

已从在大肠杆菌中表达的基因产物获得了光合细菌红螺菌中1,5-二磷酸核酮糖羧化酶二聚体形式的三种晶体形态。由包含酶-激活剂氨基甲酸盐-Mg2+-2'-羧基阿拉伯糖醇-1,5-二磷酸的四聚体复合物形成的A型晶体在此显示没有配体。相比之下，与菠菜的十六聚体L8S8酶形成的四聚体复合物晶体同时含有激活剂氨基甲酸盐和2'-羧基阿拉伯糖醇-1,5-二磷酸。红螺菌酶的B型晶体为单斜晶系，空间群P2(1)，晶胞参数a = 65.5 Å，b = 70.6 Å，c = 104.1 Å，β = 92.1°，每个不对称单元有两个亚基。旋转函数计算显示有一个垂直于单斜b轴的非晶体学2重轴。C型晶体为正交晶系（空间群P2(1)2(1)2(1)），晶胞参数a = 79.4 Å，b = 100.1 Å，c = 131.0 Å。在传统X射线源上，单斜晶体形态的衍射分辨率至少为2.0 Å。