title: Interaction between DAHP synthase and chorismate mutase endows new regulation on DAHP synthase activity in Corynebacterium glutamicum.
abstract: Previous research on Corynebacterium glutamicum revealed that 3-deoxy-D-arabino-heptulosonate 7-phosphate synthase (DSCg, formerly DS2098) interacts with chorismate mutase (CMCg, formerly CM0819). In this study, we investigated the interaction by means of structure-guided mutation and enzymatic assays. Our results show that the interaction imparted a new mechanism for regulation of DAHP activity: In the absence of CMCg, DSCg activity was not regulated by prephenate, whereas in the presence of CMCg, prephenate markedly inhibited DSCg activity. Prephenate competed with the substrate phosphoenolpyruvate, and the inhibition constant (K i) was determined to be 0.945 mM. Modeling based on the structure of the complex formed between DAHP synthase and chorismate mutase of Mycobacterium tuberculosis predicted the interaction surfaces of the putative DSCg-CMCg complex. The amino acid residues and structural domains that contributed to the interaction surfaces were experimentally identified to be the (212)SPAGARYE(219) sequence of DSCg and the (60)SGGTR(64) loop and C-terminus ((97)RGKLG(101)) of CMCg.
authors: State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, People's Republic of China.
authors: Pan-Pan
authors: PP
authors: Li
authors: De-Feng
authors: DF
authors: Li
authors: Di
authors: D
authors: Liu
authors: Yi-Ming
authors: YM
authors: Liu
authors: Chang
authors: C
authors: Liu
authors: Shuang-Jiang
authors: SJ
authors: Liu
mesh_terms: D010723:3-Deoxy-7-Phosphoheptulonate Synthase / Q000096:biosynthesis*; D002826:Chorismate Mutase / Q000378:metabolism*; D048230:Corynebacterium glutamicum / Q000235:genetics* / Q000378:metabolism*; D003509:Cyclohexanecarboxylic Acids / Q000378:metabolism; D053138:Cyclohexenes / Q000378:metabolism; D004252:DNA Mutational Analysis; D015971:Gene Expression Regulation, Enzymologic; D008958:Models, Molecular; D050505:Mutant Proteins / Q000235:genetics / Q000378:metabolism; D010728:Phosphoenolpyruvate / Q000378:metabolism; D011485:Protein Binding; D025941:Protein Interaction Mapping
chemical_list: D003509:Cyclohexanecarboxylic Acids; D053138:Cyclohexenes; D050505:Mutant Proteins; D010728:Phosphoenolpyruvate; D010723:3-Deoxy-7-Phosphoheptulonate Synthase; D002826:Chorismate Mutase; C005550:prephenic acid