重组人鸟氨酸氨基转移酶的结晶及初步X射线衍射研究

Crystallization and preliminary X-ray diffraction studies of recombinant human ornithine aminotransferase.

作者信息

Shen B W, Ramesh V, Mueller R, Hohenester E, Hennig M, Jansonius J N

机构信息

Chemistry Department, Purdue University, W. Lafayette, IN.

出版信息

J Mol Biol. 1994 Oct 14;243(1):128-30. doi: 10.1006/jmbi.1994.1637.

DOI:10.1006/jmbi.1994.1637

PMID:7932736

Abstract

Human liver ornithine aminotransferase was expressed in Escherichia coli and purified by ammonium sulfate fractionation and anion exchange column chromatography. The purified recombinant enzyme is fully active and crystallized readily over a wide range of polyethylene glycol concentrations. The crystals belong to the trigonal space group P3(1)21 (or its enantiomorph P3(2)21) with unit cell parameters a = b = 116.3 A, and c = 190.0 A, alpha = beta = 90 degrees, gamma = 120 degrees. There are three monomers per asymmetric unit. Self-rotation function studies revealed both 2-fold and 3-fold non-crystallographic symmetry, with the local 3-fold axis being tilted 15 degrees from the c axis and perpendicular to a crystallographic dyad. A complete native data set to 2.3 A resolution was collected using synchrotron radiation.

摘要

人肝脏鸟氨酸转氨酶在大肠杆菌中表达，并通过硫酸铵分级分离和阴离子交换柱色谱法进行纯化。纯化后的重组酶具有完全活性，并且在很宽的聚乙二醇浓度范围内易于结晶。晶体属于三方晶系空间群P3(1)21（或其对映体P3(2)21），晶胞参数a = b = 116.3 Å，c = 190.0 Å，α = β = 90°，γ = 120°。每个不对称单元中有三个单体。自旋转函数研究揭示了2次和3次非晶体学对称性，局部3次轴相对于c轴倾斜15°并垂直于一个晶体学二重轴。使用同步辐射收集了分辨率为2.3 Å的完整天然数据集。