Effect of amino acid substitutions in a potential metal-binding site of AnfA on expression from the anfH promoter in Azotobacter vinelandii

• Published in: Journal of Bacteriology Vol. 176; no. 19; pp. 6139 - 6142
• Main Authors: Loveless, T.M, Bishop, P.E
• Format: Journal Article
• Language: English
• Published: United States American Society for Microbiology 01-10-1994
• Subjects: ADN; Amino acids; Azotobacter - enzymology; Azotobacter - genetics; Azotobacter - growth & development; AZOTOBACTER VINELANDII; Bacterial Proteins; Bacteriology; Base Sequence; CATION; CATIONES; DNA Mutational Analysis; DNA-Binding Proteins - genetics; GENE; Gene Expression Regulation, Bacterial; GENES; GENETICA; GENETIQUE; METAL; METALES; Molecular Sequence Data; MOLIBDENO; MOLYBDENE; Molybdenum - metabolism; Mutation; NITROGENASA; NITROGENASE; Nitrogenase - biosynthesis; Nitrogenase - genetics; Promoter Regions, Genetic - genetics; PROTEINAS; PROTEINE; Recombinant Fusion Proteins - biosynthesis; Trans-Activators - genetics; Transcription, Genetic; VANADIO; VANADIUM; Vanadium - metabolism
• ISSN: 0021-9193; 1098-5530; 1067-8832
• DOI: 10.1128/jb.176.19.6139-6142.1994

AnfA, an activator required for transcription of the structural genes encoding nitrogenase 3 (anfHDGK) in Azotobacter vinelandii, has a potential metal-binding site [(S19)H(C21)FTGE(C26)R] in its N terminus. Growth studies and expression of an anfH-lacZ fusion in mutants containing amino acid substitutions in this site indicate that Ser-19 is not required for AnfA activity whereas Cys-21 and Cys-26 are required. Residual expression of the anfH-lacZ fusion in AnfA- mutants was found to be due to activation by VnfA, the activator required for expression of genes encoding nitrogenase 2