title: Cloning and nucleotide sequence of the DNA gyrase gyrA gene from the fish pathogen Aeromonas salmonicida.
abstract: The DNA gyrase gyrA gene from the fish pathogen Aeromonas salmonicida 2148/89 was cloned, and the nucleotide sequence was determined. An open reading frame of 2,766 nucleotides was identified and was found to encode a protein of 922 amino acids with a calculated molecular mass of 101.1 kDa. The derived amino acid sequence shared a high degree of identity with other DNA gyrase A proteins, in particular, with other gram-negative GyrA sequences. When the amino acid sequence of A. salmonicida GyrA was compared with that of Escherichia coli GyrA, a number of conserved residues were present at identical coordinates, including the catalytic Tyr residue at position 122 (Tyr-122) and residues whose substitution confers quinolone resistance, notably, Ser-83, Ala-67, Gly-81, Asp-87, Ala-84, and Gln-106. An intragenic region corresponding to 48 amino acids, which is not present in E. coli or other bacteria, was identified in the C-terminal part of A. salmonicida GyrA. This intragenic region shared sequence identity with various DNA-binding proteins of both prokaryotic and eukaryotic origins.
authors.affiliation: Department of Pharmacology, Microbiology and Food Hygiene, Norwegian College of Veterinary Medicine, Oslo, Norway. hanneo@extern.uio.no
authors.forename: H
authors.initials: H
authors.lastname: Oppegaard
authors.forename: H
authors.initials: H
authors.lastname: Sørum
mesh_terms: D000333:Aeromonas / Q000201:enzymology / Q000235:genetics*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004250:DNA Topoisomerases, Type II / Q000235:genetics*; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D004926:Escherichia coli / Q000235:genetics; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D012474:Salmon / Q000382:microbiology; D017422:Sequence Analysis, DNA
chemical_list: D004269:DNA, Bacterial; D004250:DNA Topoisomerases, Type II