title: Structural insight into dephosphorylation by trehalose 6-phosphate phosphatase (OtsB2) from Mycobacterium tuberculosis.
abstract: Trehalose serves as a key structural component in the cell wall of Mycobacterium tuberculosis. M. tuberculosis trehalose-6-phosphate phosphatase (MtbTPP), an essential enzyme in the trehalose biosynthesis OtsAB pathway, catalyzes the dephosphorylation of trehalose-6-phosphate (trehalose-6-P) to generate trehalose, and plays a critical role in M. tuberculosis survival-associated cell wall formation and permeability. Therefore, MtbTPP (OtsB2) is considered a promising potential target for discovery of antimicrobial drugs. However, the absence of structural information of MtbTPP restrains our understanding of its underlying catalytic mechanism. Here, we report the high-resolution crystal structures of apo active MtbTPP and its trehalose-6-P bound complex. The apo structure presents a canonical haloacid dehalogenase superfamily structural fold plus an extra N-terminal domain. The catalytic center is located in a positively charged cleft between the hydrolase domain and the cap domain, demonstrating a highly conserved substrate binding pocket. The role of residues interacting with the substrate in catalysis were probed by site-directed mutagenesis. Asp147, Asp149, Asp330, and Asp331 were found to be pivotal for the enzymatic activity of MtbTPP. The MtbTPP structures reported here provide insight into a key step in the biosynthesis of trehalose, which would facilitate future development of anti-TB therapeutics.-Shan, S., Min, H., Liu, T., Jiang, D., Rao, Z. Structural insight into dephosphorylation by trehalose 6-phosphate phosphatase (OtsB2) from Mycobacterium tuberculosis.
authors: National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China; shanshan@moon.ibp.ac.cn.
authors: Shan
authors: S
authors: Shan
authors: State Key Laboratory of Plant Genomics, Chinese Academy of Sciences, Beijing, China.|National Center for Plant Gene Research-Beijing, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China; and.
authors: Haowei
authors: H
authors: Min
authors: College of Life Sciences, Nankai University, Tianjin, China.
authors: Ting
authors: T
authors: Liu
authors: College of Life Sciences, Nankai University, Tianjin, China.
authors: Dunquan
authors: D
authors: Jiang
authors: National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.|College of Life Sciences, Nankai University, Tianjin, China.
authors: Zihe
authors: Z
authors: Rao
mesh_terms: D000595:Amino Acid Sequence / Q000235:genetics; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed / Q000379:methods; D009169:Mycobacterium tuberculosis / Q000201:enzymology*; D010710:Phosphates / Q000378:metabolism; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism*; D010766:Phosphorylation; D013403:Sugar Phosphates / Q000378:metabolism; D014199:Trehalose / Q000031:analogs & derivatives / Q000378:metabolism
chemical_list: D010710:Phosphates; D013403:Sugar Phosphates; C082722:trehalose-6-phosphate; D014199:Trehalose; C023178:trehalose-phosphatase; D010744:Phosphoric Monoester Hydrolases
keywords: MtbTPP; crystal structure; drug discovery