Molecular characterization of a chromosomal determinant conferring resistance to zinc and cobalt ions in Staphylococcus aureus

• Published in: Journal of bacteriology Vol. 180; no. 16; pp. 4024 - 4029
• Main Authors: Xiong, A, Jayaswal, R K
• Format: Journal Article
• Language: English
• Published: United States American Society for Microbiology 01.08.1998
• Subjects: Amino Acid Sequence; Bacterial Proteins - genetics; Bacteriology; Chromosome Mapping; Chromosomes, Bacterial; Cloning, Molecular; Cobalt - pharmacology; Deoxyribonucleic acid; DNA; DNA, Bacterial - genetics; Drug Resistance, Microbial - genetics; Genetic Complementation Test; Genetics and Molecular Biology; Ions; Metals; Molecular Sequence Data; Mutation - genetics; Open Reading Frames; RNA, Messenger - genetics; Sequence Homology, Amino Acid; Staphylococcus aureus - drug effects; Staphylococcus aureus - genetics; Transcription, Genetic; Zinc - pharmacology
• ISSN: 0021-9193; 1098-5530
• DOI: 10.1128/JB.180.16.4024-4029.1998

A DNA fragment conferring resistance to zinc and cobalt ions was isolated from a genomic DNA library of Staphylococcus aureus RN450. The DNA sequence analysis revealed two consecutive open reading frames, designated zntR and zntA. The predicted ZntR and ZntA showed significant homology to members of ArsR and cation diffusion families, respectively. A mutant strain containing the null allele of zntA was more sensitive to zinc and cobalt ions than was the parent strain. The metal-sensitive phenotype of the mutant was complemented by a 2.9-kb DNA fragment containing zntR and zntA. An S. aureus strain harboring multiple copies of zntR and zntA showed an increased resistance to zinc. The resistance to zinc in the wild-type strain was inducible. Transcriptional analysis indicated that zntR and zntA genes were cotranscribed. The zinc uptake studies suggested that the zntA product was involved in the export of zinc ions out of cells.