Protein Preparation, Crystallization and Preliminary X-ray Crystallographic Analysis of Smu.260 From Streptococcus mutans--a Cariogenic Dental Pathogen
- VernacularTitle:龋齿致病菌变形链球菌蛋白Smu.260的制备、结晶及初级晶体学分析
- Author:
Xiaoyan ZHANG
;
Wei MI
;
Yanfeng ZHOU
;
Xiangyu LIU
;
Lanfen LI
;
Yuhe LIANG
;
Shicheng WEI
;
Xiaodong SU
- Publication Type:Journal Article
- Keywords:
Streptococcus mutans;
dental caries;
Smu.260;
protein crystallography
- From:
Progress in Biochemistry and Biophysics
2005;32(3):217-220
- CountryChina
- Language:Chinese
-
Abstract:
Smu. 260 encodes a putative protein of 200 residues in Streptococcus mutans, a primary pathogen for human dental caries. Smu. 260 was cloned into expression vector pET28a and expressed in good amount trom the E. coli strain BL21 (DE3). Smu.260 protein was purified to homogeneity in a two-step procedure of Ni2+ chelating and size exclusion chromatography. The purified protein exists in two forms, a dimer form about 46 ku with yellow color and a tetramer form without apparent color. Crystals were obtained from the dimer protein by hanging-drop vapor-diffusion method. The crystals diffracted to about 2.3 A resolution and belong to orthorhombic space group P212121 with cell dimensions of a = 89.88A, b = 90.91 A, c = 105.17 A. The asymmetric unit is expected to contain two dimers with solvent content of 53%.
