title: A multicopper oxidase contributes to the copper tolerance of Brucella melitensis 16M.
abstract: Copper is a potent antimicrobial agent. Multiple mechanisms of copper tolerance are utilized by some pathogenic bacteria. BMEII0580, which is significantly similar to the multicopper oxidase from Escherichia coli, was predicted to be the probable blue copper protein YacK precursor in Brucella melitensis 16M, and was designated as Brucella multicopper oxidase (BmcO). A bioinformatics analysis indicated that the typical motifs of multicopper oxidases are present in BmcO. BmcO, the expression of which was up-regulated by copper, could catalyze the oxidation of 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), dimethoxyphenol (DMP) and para-phenylenediamine (pPD), which are widely used as substrates for multicopper oxidase. Additionally, BmcO exhibited ferroxidase activity, which indicated that it might play an important role in the Fe(2+) uptake of B. melitensis. Importantly, the mutant strain 16MΔbmcO was more sensitive to copper than the wild-type strain B. melitensis 16M as well as its complementation strain 16MΔbmcO(bmcO). The infection assays of cells showed that similar bacterial numbers of B. melitensis 16M, 16MΔbmcO and 16MΔbmcO(bmcO) strains were recovered from the infected macrophages. This result indicated that BmcO was not essential for B. melitensis intracellular growth. In conclusion, our results confirm that BmcO is a multicopper oxidase and contributes to the copper tolerance of B. melitensis 16M.
authors.affiliation: Key Laboratory of Animal Epidemiology and Zoonosis of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
authors.forename: Tonglei
authors.initials: T
authors.lastname: Wu
authors.affiliation: Key Laboratory of Animal Epidemiology and Zoonosis of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China Animal Science and Technology College, Hebei North University, Zhangjiakou 075135, China.
authors.forename: Shaohua
authors.initials: S
authors.lastname: Wang
authors.affiliation: Animal Science and Technology College, Beijing University of Agriculture, Beijing 102206, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Key Laboratory of Animal Epidemiology and Zoonosis of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Peng
authors.affiliation: Key Laboratory of Animal Epidemiology and Zoonosis of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
authors.forename: Yanli
authors.initials: Y
authors.lastname: Lu
authors.affiliation: Key Laboratory of Animal Epidemiology and Zoonosis of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China wuqm@cau.edu.cn.
authors.forename: Qingmin
authors.initials: Q
authors.lastname: Wu
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D017347:Brucella melitensis / Q000187:drug effects* / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D002006:Brucellosis / Q000382:microbiology; D002570:Ceruloplasmin / Q000378:metabolism; D003300:Copper / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial / Q000235:genetics; D005816:Genetic Complementation Test; D007501:Iron / Q000378:metabolism; D008264:Macrophages / Q000382:microbiology; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D017384:Sequence Deletion
chemical_list: D000900:Anti-Bacterial Agents; D003300:Copper; D007501:Iron; D010088:Oxidoreductases; D002570:Ceruloplasmin
keywords: Brucella; copper tolerance; multicopper oxidase