Nucleotide sequences and genetic analysis of hydrogen oxidation (hox) genes in Azotobacter vinelandii
| Autor: | Robert L. Robson, L. E. Mortenson, Angeli Lal Menon |
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| Rok vydání: | 1992 |
| Předmět: |
Reading Frames
Hydrogenase Operon Molecular Sequence Data Biology Microbiology Insertional mutagenesis Sequence Homology Nucleic Acid Metalloproteins Amino Acid Sequence Cloning Molecular ORFS Molecular Biology Gene Genetics Azotobacter vinelandii Base Sequence Structural gene biology.organism_classification Mutagenesis Insertional Open reading frame Biochemistry Multigene Family bacteria Oxidation-Reduction Research Article Hydrogen |
| Zdroj: | Journal of Bacteriology. 174:4549-4557 |
| ISSN: | 1098-5530 0021-9193 |
| DOI: | 10.1128/jb.174.14.4549-4557.1992 |
| Popis: | Azotobacter vinelandii contains a heterodimeric, membrane-bound [NiFe]hydrogenase capable of catalyzing the reversible oxidation of H2. The beta and alpha subunits of the enzyme are encoded by the structural genes hoxK and hoxG, respectively, which appear to form part of an operon that contains at least one further potential gene (open reading frame 3 [ORF3]). In this study, determination of the nucleotide sequence of a region of 2,344 bp downstream of ORF3 revealed four additional closely spaced or overlapping ORFs. These ORFs, ORF4 through ORF7, potentially encode polypeptides with predicted masses of 22.8, 11.4, 16.3, and 31 kDa, respectively. Mutagenesis of the chromosome of A. vinelandii in the area sequenced was carried out by introduction of antibiotic resistance gene cassettes. Disruption of hoxK and hoxG by a kanamycin resistance gene abolished whole-cell hydrogenase activity coupled to O2 and led to loss of the hydrogenase alpha subunit. Insertional mutagenesis of ORF3 through ORF7 with a promoterless lacZ-Kmr cassette established that the region is transcriptionally active and involved in H2 oxidation. We propose to call ORF3 through ORF7 hoxZ, hoxM, hoxL, hoxO, and hoxQ, respectively. The predicted hox gene products resemble those encoded by genes from hydrogenase-related operons in other bacteria, including Escherichia coli and Alcaligenes eutrophus. |
| Databáze: | OpenAIRE |
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