A spontaneous point mutation in the aac(6')-Ib' gene results in altered substrate specificity of aminoglycoside 6'-N-acetyltransferase of a Pseudomonas fluorescens strain.
The aac(6')-Ib' gene from Pseudomonas fluorescens BM2687, encoding an aminoglycoside 6'-N-acetyltransferase type II which confers resistance to gentamicin but not to amikacin, was characterized. Nucleotide sequence determination indicated total identity between aac(6')-Ib' and the aac(6')-Ib gene from Pseudomonas aeruginosa BM2656 [1] with the exception of a C-to-T transition that results in a serine to leucine substitution at position 83 of the deduced polypeptide. The aac(6')-Ib gene specifies a type I enzyme which confers resistance to amikacin but not to gentamicin [2]. It thus appears that the point mutation detected is responsible for enzymic altered substrate specificity.
Lambert
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T
Chatenay-Malabry, Centre d'Etudes Pharmaceutiques, France.
Ploy
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MC
Courvalin
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D000123:Acetyltransferases / Q000235:genetics*; D000583:Amikacin / Q000494:pharmacology; D001483:Base Sequence; D003001:Cloning, Molecular; D004352:Drug Resistance, Microbial / Q000235:genetics; D005784:Gene Amplification; D005798:Genes, Bacterial / Q000235:genetics*; D005839:Gentamicins / Q000494:pharmacology; D008969:Molecular Sequence Data; D017354:Point Mutation / Q000235:genetics*; D011551:Pseudomonas fluorescens / Q000235:genetics*; D017422:Sequence Analysis, DNA; D013379:Substrate Specificity / Q000235:genetics
D005839:Gentamicins; D000583:Amikacin; D000123:Acetyltransferases; C056532:aminoglycoside N(6')-acetyltransferase