title: Identification and mutational analysis of rfbG, the gene encoding CDP-D-glucose-4,6-dehydratase, isolated from free living soil bacterium Azotobacter vinelandii.
abstract: We have identified the rfbG from a non-symbiotic and non-pathogenic soil bacterium, Azotobacter vinelandii. The nucleotide sequence analysis of the rfbG revealed an open reading frame that encodes a peptide of 360 amino acids. This deduced peptide shares 57% homology with the RfbG of Synechocystis and 47% homology with the RfbG of Yersinia pseudotuberculosis. The previously identified short-chain dehydrogenases/reductases family signature sequence is conserved in the sequence of the RfbG of A. vinelandii. Southern blotting analysis of A. vinelandii chromosome by probed with 1.1 kb PstI DNA fragment corresponding to rfbG revealed that it is present as single copy on A. vinelandii chromosome. Disrupting the rfbG present on the chromosome of A. vinelandii, by insertion of kanamycin resistance marker via homologous recombination, resulted in drastic changes in the growth characteristics. The rfbG-negative A. vinelandii grown in liquid medium exhibited agglutination that is characteristic of rfb- mutants of other bacteria, suggesting that we have cloned the functional copy of the rfbG of A. vinelandii.
authors.affiliation: Department of Biological Sciences, Bowling Green State University, Ohio 43403, USA. ngavini@bgnet.bgsu.edu
authors.forename: N
authors.initials: N
authors.lastname: Gavini
authors.forename: B S
authors.initials: BS
authors.lastname: Hausman
authors.forename: L
authors.initials: L
authors.lastname: Pulakat
authors.forename: R P
authors.initials: RP
authors.lastname: Schreiner
authors.forename: J A
authors.initials: JA
authors.lastname: Williamson
mesh_terms: D000595:Amino Acid Sequence; D016948:Azotobacter vinelandii / Q000201:enzymology* / Q000235:genetics*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification; D001483:Base Sequence; D003001:Cloning, Molecular; D004252:DNA Mutational Analysis; D005798:Genes, Bacterial / Q000502:physiology; D006836:Hydro-Lyases / Q000235:genetics* / Q000302:isolation & purification; D008969:Molecular Sequence Data; D019081:O Antigens / Q000737:chemistry; D016415:Sequence Alignment; D012988:Soil Microbiology
chemical_list: D001426:Bacterial Proteins; D019081:O Antigens; C079397:rfb protein, Bacteria; D006836:Hydro-Lyases; C089119:CDP-glucose 4,6-dehydratase