title: Presence of strA-strB gene within a streptomycin-resistance operon in a clinical isolate of Shigella flexneri.
abstract: Three aminoglycoside-modifying enzymes (AMEs) were produced by a clinical isolate of Shigella flexneri which was resistant to gentamicin, tobramycin, netilmicin, kanamycin, sisomicin and streptomycin: acetyltransferase (AAC) (3)-II-type, and phosphotransferase (APH) (3")- and (6)-type enzymes. The aminoglycoside-resistance genes were located on a 75-Kb plasmid. Two genes, strA-HK and strB-HK, in a transcriptional unit were found to code for streptomycin-resistance. The genetic organization and sequence of this transcriptional unit were identical to those of strA and strB in plasmid RSF1010. strA-HK and strB-HK when expressed separately produced functional enzymes. Our substrate profile study on the crude extracts of StrA-HK and StrB-HK proteins confirmed that StrA-HK was an APH(3")-type and showed that StrB-HK was a member of the APH(6) family.
authors.affiliation: Department of Biochemistry, Chinese University of Hong Kong, Hong Kong.
authors.forename: P C
authors.initials: PC
authors.lastname: Shaw
authors.forename: A C
authors.initials: AC
authors.lastname: Liang
authors.forename: K M
authors.initials: KM
authors.lastname: Kam
authors.forename: J M
authors.initials: JM
authors.lastname: Ling
mesh_terms: D004352:Drug Resistance, Microbial / Q000235:genetics; D009876:Operon / Q000235:genetics; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics*; D015183:Restriction Mapping; D017386:Sequence Homology, Amino Acid; D012763:Shigella flexneri / Q000235:genetics*; D013307:Streptomycin
chemical_list: D017853:Phosphotransferases (Alcohol Group Acceptor); C022680:streptomycin 6-kinase; C022679:streptomycin 3''-kinase; D013307:Streptomycin