Abstract

Article info Vol. 7  No. 3   pp.  61 ~ 66
Title Cytosolic 5′-Methylthioadenosine/S-Adenosylhomocysteine Nucleosidase MtaN from Mycobacterium. smegmatis: purification, crystallization and X-ray crystallographic analysis
Authors Lulu Wang1,2,3, Yuanyuan Chen2,3, Wei Liu2,3, Jing Lan2,3, Fei Shang2,3, Nam-Chul Ha4, Yuesheng Dong1*, Chunshan Quan2,3* and Yongbin Xu2,3*
Institutions 1School of Life Science and Biotechnology, Dalian University of Technology, Dalian 116024, Liaoning, China 2Department of Bioengineering, College of Life Science, Dalian Minzu University, Dalian 116600, Liaoning, China 3Key Laboratory of Biotechnology and Bioresources Utilization (Dalian Minzu University), Ministry of Education, China 4Department of Agricultural Biotechnology, College of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea *Correspondence: yongbinxu@dlnu.edu.cn, hanc210@snu.ac.kr, mikyeken@dlnu.edu.cn
Abstract Mycobacterium tuberculosis is a dangerous pathogen, and it can cause the most deadly disease tuberculosis (TB). Nonpathogenic Mycobacterium smegmatis is an important model for studying the M. tuberculosis. M. smegmatis 5’-Methylthioadenosine/S-adenosyl-L-homocysteine nucleosidases (MtaNs) catalyze the hydrolysis of adenine from 5’-methylthioadenosine (MTA), MtaNs cleave the glycosidic bond of MTA or S-adenosylhomocysteine (SAH) irreversibly. In this study, MtaN from M. smegmatis (MsMtaN) was successfully expressed and purified using Ni-NTA affinity, Q anionexchange and gel-filtration chromatography. The protein crystal was obtained and diffracted to a resolution of 2.0 Å. The crystal belonged to the orthorhombic space group P1211, with unit-cell parameters of a =57.6, b = 172.6, and c = 183.3 Å. The Matthews coefficient and solvent content were estimated to be 2.32 Å3 Da-1 and 47%, respectively, assuming that the asymmetric unit contained only one recombinant protein molecule. Size-exclusion chromatography suggested that MsMtaN prefer to exist as tetramer in solution.