嗜热栖热放线菌内切葡聚糖酶CelC两种晶体形式的表征

Characterization of two crystal forms of Clostridium thermocellum endoglucanase CelC.

作者信息

Dominguez R, Souchon H, Alzari P M

机构信息

Unité d'Immunologie Structurale, URA 359 CNRS, Institut Pasteur, Paris, France.

出版信息

Proteins. 1994 Jun;19(2):158-60. doi: 10.1002/prot.340190209.

DOI:10.1002/prot.340190209

PMID:8090710

Abstract

Endoglucanase CelC from Clostridium thermocellum expressed in Escherichia coli has been crystallized in two different crystal forms by the hanging drop method. Crystals of form I were grown with polyethylene glycol as a precipitant. They are orthorhombic, space group P2(1)2(1)2(1), with cell dimensions a = 51.4 A, b = 84.3 A, and c = 87.5 A. Crystals of form II, obtained in ammonium sulfate solutions, belong to the tetragonal space group P4(1)2(1)2 (or P4(3)2(1)2) with cell dimensions of a = b = 130.7 A and c = 69.6 A. Diffraction data to 2.8 A resolution were observed for both crystal forms with a rotating anode generator. Preliminary oscillation images of the orthorhombic form I crystals using a synchrotron radiation source show diffraction to 2.2 A resolution, indicating that these crystals are suitable for high resolution crystallographic analysis.

摘要

在大肠杆菌中表达的来自嗜热栖热菌的内切葡聚糖酶CelC已通过悬滴法结晶为两种不同的晶体形式。I型晶体是在聚乙二醇作为沉淀剂的条件下生长的。它们属于正交晶系，空间群为P2(1)2(1)2(1)，晶胞参数a = 51.4 Å，b = 84.3 Å，c = 87.5 Å。在硫酸铵溶液中获得的II型晶体属于四方晶系空间群P4(1)2(1)2（或P4(3)2(1)2），晶胞参数a = b = 130.7 Å，c = 69.6 Å。使用旋转阳极发生器对两种晶体形式都观察到了分辨率为2.8 Å的衍射数据。使用同步辐射源对正交晶系I型晶体进行的初步振荡图像显示衍射分辨率达到2.2 Å，表明这些晶体适合进行高分辨率晶体学分析。