Guan Li-Jun, Lee Woo Cheol, Wang Shipeng, Ohshiro Takashi, Izumi Yoshikazu, Ohtsuka Jun, Tanokura Masaru
Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, University of Tokyo, Bunkyo-ku, Tokyo, Japan.
Department of Biotechnology, Tottori University, Koyama-Minami, Tottori, Japan.
FEBS J. 2015 Aug;282(16):3126-35. doi: 10.1111/febs.13216. Epub 2015 Feb 11.
The release of SO2 from petroleum products derived from crude oil, which contains sulfur compounds such as dibenzothiophene (DBT), leads to air pollution. The '4S' metabolic pathway catalyzes the sequential conversion of DBT to 2-hydroxybiphenyl via three enzymes encoded by the dsz operon in several bacterial species. DszC (DBT monooxygenase), from Rhodococcus erythropolis D-1 is involved in the first two steps of the '4S' pathway. Here, we determined the first crystal structure of FMN-bound DszC, and found that two distinct conformations occur in the loop region (residues 131-142) adjacent to the active site. On the basis of the DszC-FMN structure and the previously reported apo structures of DszC homologs, the binding site for DBT and DBT sulfoxide is proposed.
The atomic coordinates and structure factors for apo-DszC (PDB code: 3X0X) and DszC-FMN (PDB code: 3X0Y) have been deposited in the Protein Data Bank (http://www.rcsb.org).
原油衍生的石油产品中会释放出二氧化硫，原油中含有二苯并噻吩（DBT）等含硫化合物，这会导致空气污染。“4S”代谢途径通过几种细菌物种中dsz操纵子编码的三种酶催化DBT依次转化为2-羟基联苯。来自红平红球菌D-1的DszC（DBT单加氧酶）参与“4S”途径的前两步。在此，我们确定了结合FMN的DszC的首个晶体结构，并发现活性位点相邻的环区域（残基131-142）出现两种不同构象。基于DszC-FMN结构和先前报道的DszC同源物的无辅基结构，提出了DBT和DBT亚砜的结合位点。
无辅基DszC（PDB代码：3X0X）和DszC-FMN（PDB代码：3X0Y）的原子坐标和结构因子已存入蛋白质数据库（http://www.rcsb.org）。
