Characterization of the glnK-amtB operon of Azotobacter vinelandii

• Published in: Journal of Bacteriology Vol. 180; no. 12; pp. 3260 - 3264
• Main Authors: Meletzus, D. (Universitat Bielefeld, Bielefeld, Germany.), Rudnick, P, Doetsch, N, Green, A, Kennedy, C
• Format: Journal Article
• Language: English
• Published: United States American Society for Microbiology 01-06-1998
• Series: Note
• Subjects: AMINO ACID SEQUENCES; AMMONIA; AMMONIAC; AMONIACO; ANION; ANIONES; ANIONS; ARN MENSAJERO; ARN MESSAGER; AZOTOBACTER VINELANDII; Azotobacter vinelandii - genetics; Azotobacter vinelandii - metabolism; Bacteria; BACTERIAL PROTEINS; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Bacteriology; Biological Transport, Active - genetics; Carrier Proteins - genetics; Carrier Proteins - metabolism; Cation Transport Proteins; CELL MEMBRANES; CHEMICAL COMPOSITION; COMPOSICION QUIMICA; COMPOSITION CHIMIQUE; DNA, Bacterial - genetics; Escherichia coli - genetics; Escherichia coli Proteins; EXPRESION GENICA; EXPRESSION DES GENES; GENBANK/U91902; GENE; GENE EXPRESSION; GENES; Genes, Bacterial; Genetics and Molecular Biology; GLNK GENE; ION; ION TRANSPORT; IONES; IONS; MEMBRANAS CELULARES; MEMBRANE CELLULAIRE; MESSENGER RNA; Methylamines - metabolism; METHYLAMMONIUM; MICROBIAL PROTEINS; MOLECULAR SEQUENCE DATA; MUTANT; MUTANTES; MUTANTS; Mutation; Nitrogen Fixation - genetics; NUCLEOTIDE SEQUENCE; Operon; PII Nitrogen Regulatory Proteins; PLASMA MEMBRANES; PROTEINAS MICROBIANAS; PROTEINE MICROBIENNE; Proteins; SECUENCIA NUCLEOTIDICA; SEQUENCE NUCLEOTIDIQUE; STRUCTURAL GENES
• ISSN: 0021-9193; 1098-5530; 1067-8832
• DOI: 10.1128/jb.180.12.3260-3264.1998

To determine whether in Azotobacter vinelandii the PII protein influences the regulation of nif gene expression in response to fluxes in the ammonium supply, the gene encoding PII was isolated and characterized. Its deduced translation product was highly similar to PII proteins from other organisms, with the greatest degree of relatedness being exhibited to the Escherichia coli glnK gene product. A gene designated amtB was found downstream of and was cotranscribed with glnK as in E. coli. The AmtB protein is similar to functionally characterized ammonium transport proteins from a few other eukaryotes and one other prokaryote. glnK and amtB comprise an operon. Attempts to isolate a stable glnK mutant strain were unsuccessful, suggesting that glnK, like glnA, is an essential gene in A. vinelandii. amtB mutants were isolated, and although growth on limiting amounts of ammonium was similar in the mutant and wild-type strains, the mutants were unable to transport [14C]methylammonium