CuiD is a crucial gene for survival at high copper environment in Salmonella enterica serovar Typhimurium.
Copper ion is an essential micronutrient but it is also extremely cytotoxic when it exists in excess. Our studies have shown that Salmonella enterica serovar Typhimurium can survive potentially lethal copper exposures by the way of copper efflux system. A copper ion inducible gene was identified in virulent S. typhimurium by using the technique of MudJ (Km, lac)-directed lacZYA operon fusions. A copper ion inducible strain LF153 (cuiD::MudJ) has been identified. The cuiD mutant exhibits a copper sensitive phenotype but possesses normal resistance to other metal ions, and lost DMP oxidase activity. Therefore, we suggest that cuiD is an important gene for copper homeostasis and the copper resistance response. The copper sensitive phenotype was complemented by pYL3.0 carrying cuiD+. Sequence analysis showed cuiD contains 1,614 bp encoding a 536 amino acid with a 27 amino acid signal peptide and a 509 amino acid residues comprising the mature peptide. The CuiD shows 81% homology to YacK, a putative multicopper oxidases which extrudes copper in Escherichia coli. This ORF contains four conserved regions that contain 12 copper ligands (types 1, 2, and 3) present in various copper homeostasis responsible proteins. The H2O2 sensitive phenotype of the cuiD mutant indicates that cuiD may be involved in oxidative stress response.
Lim
Sung-Young
SY
Department of Microbiology, Han Nam University, Daejeon, Korea.
Joe
Min-Ho
MH
Song
Sang-Sun
SS
Lee
Mun-Hee
MH
Foster
John W
JW
Park
Yong-Keun
YK
Choi
Soon-Yong
SY
Lee
In-Soo
IS
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D017124:Conserved Sequence; D003300:Copper / Q000378:metabolism* / Q000633:toxicity; D004926:Escherichia coli / Q000235:genetics; D029968:Escherichia coli Proteins; D008969:Molecular Sequence Data; D009154:Mutation; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000235:genetics; D012486:Salmonella typhimurium / Q000235:genetics* / Q000378:metabolism*; D016415:Sequence Alignment
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D003300:Copper; D010088:Oxidoreductases; C499679:cueO protein, E coli