title: Improvement of L-arginine production by overexpression of a bifunctional ornithine acetyltransferase in Corynebacterium crenatum.
abstract: Ornithine acetyltransferase (EC 2.3.1.35; OATase) gene (argJ) from the L-arginine-producing mutant Corynebacterium crenatum SYPA5-5 was cloned, sequenced, and expressed in Escherichia coli BL21 (DE3). Analysis of the argJ sequence revealed that the argJ coded a polypeptide of 388 amino acids with a calculated molecular weight of 39.7 kDa. In this study, the function of the OATase (argJ) of C. crenatum SYPA5-5 has been identified as a conserved ATML sequence for the autolysis of the protein to α- and β-subunits. When the argJ regions corresponding to the α- and β-subunits were cloned and expressed separately in E. coli BL21, OATase activities were abolished. At the same time, a functional study revealed that OATase from C. crenatum SYPA5-5 was a bifunctional enzyme with the functions of acetylglutamate synthase (EC 2.3.1.1, NAGS) and acetylornithine deacetylase (EC 3.5.1.16, AOase) activities. In order to investigate the effects of the overexpression of the argJ gene on L: -arginine production, the argJ gene was inserted into pJCtac to yield the recombinant shuttle plasmid pJCtac-argJ and then transformed into C. crenatum SYPA5-5. The results showed that the engineered strains could not only express more OATase (90.9%) but also increase the production of L: -arginine significantly (16.8%).
authors.affiliation: Laboratory of Pharmaceutical Engineering, School of Medicine and Pharmaceutics, Jiangnan University, Wuxi 214122, People's Republic of China.
authors.forename: Wenfang
authors.initials: W
authors.lastname: Dou
authors.forename: Meijuan
authors.initials: M
authors.lastname: Xu
authors.forename: Dongmei
authors.initials: D
authors.lastname: Cai
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Zhang
authors.forename: Zhiming
authors.initials: Z
authors.lastname: Rao
authors.forename: Zhenghong
authors.initials: Z
authors.lastname: Xu
mesh_terms: D000123:Acetyltransferases / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D001120:Arginine / Q000096:biosynthesis* / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D003001:Cloning, Molecular; D003352:Corynebacterium / Q000201:enzymology* / Q000235:genetics; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D015870:Gene Expression; D007218:Industrial Microbiology / Q000379:methods*; D008969:Molecular Sequence Data; D010957:Plasmids; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D014169:Transformation, Bacterial
chemical_list: D001426:Bacterial Proteins; D021122:Protein Subunits; D001120:Arginine; D000123:Acetyltransferases; C020646:glutamate acetyltransferase