title: Sequence analysis of the Rickettsia prowazekii gyrA gene.
abstract: The Rickettsia prowazekii (Rp) gyrA gene, which codes for a subunit of DNA gyrase in this obligate intracellular bacterium, has been isolated and characterized. Nucleotide sequence analysis revealed an open reading frame (ORF), initiating with a GTG start codon, of 2718 bp that could encode a protein of 905 amino acids (aa) with a calculated M(r) of 101,048. The Rp gyrase subunit A (GyrA), when compared to GyrA analogs of other bacterial species, exhibited 43 to 50% identity. Alignment of the Rp GyrA aa sequence with the other analogs revealed the presence of a span of additional aa within the putative DNA-binding domain. The lack of an ORF within 865 bp upstream from the Rp gyrA demonstrates a Rp gene organization different from that of characterized gyrA from other species. Despite the similarity to Escherichia coli GyrA, Rp GyrA did not complement an E. coli gyrA temperature-sensitive mutant. However, Rp gyrA was dominant to an E. coli gyrA96 nalidixic-acid-resistant (NalR) mutant, conferring Nal sensitivity when introduced into the NalR E. coli strain.
authors: Department of Microbiology and Immunology, University of South Alabama College of Medicine, Mobile 36688.
authors: D O
authors: DO
authors: Wood
authors: R T
authors: RT
authors: Waite
mesh_terms: D000595:Amino Acid Sequence; D001419:Bacteria / Q000201:enzymology / Q000235:genetics; D001483:Base Sequence; D003062:Codon; D027081:DNA Gyrase; D004250:DNA Topoisomerases, Type II / Q000096:biosynthesis / Q000235:genetics*; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D015698:Genomic Library; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D012283:Rickettsia prowazekii / Q000201:enzymology / Q000235:genetics*; D017386:Sequence Homology, Amino Acid
chemical_list: D003062:Codon; D046911:Macromolecular Substances; D027081:DNA Gyrase; D004250:DNA Topoisomerases, Type II