NUCLEOTIDE-SEQUENCES AND MUTATIONAL ANALYSIS OF THE STRUCTURAL GENES FOR NITROGENASE-2 OF AZOTOBACTER-VINELANDII

作者：JOERGER RD; LOVELESS TM; PAU RN; MITCHENALL LA; SIMON BH; BISHOP PE

来源：Journal of Bacteriology, 1990, 172(6): 3400-3408.

DOI：10.1128/jb.172.6.3400-3408.1990

<jats:p>The nucleotide sequence (6,559 base pairs) of the genomic region containing the structural genes for nitrogenase 2 (V nitrogenase) from Azotobacter vinelandii was determined. The open reading frames present in this region are organized into two transcriptional units. One contains vnfH (encoding dinitrogenase reductase 2) and a ferredoxinlike open reading frame (Fd). The second one includes vnfD (encoding the alpha subunit of dinitrogenase 2), vnfG (encoding a product similar to the delta subunit of dinitrogenase 2 from A. chroococcum), and vnfK (encoding the beta subunit of dinitrogenase 2). The 5'-flanking regions of vnfH and vnfD contain sequences similar to ntrA-dependent promoters. This gene arrangement allows independent expression of vnfH-Fd and vnfDGK. Mutant strains (CA80 and CA11.80) carrying an insertion in vnfH are still able to synthesize the alpha and beta subunits of dinitrogenase 2 when grown in N-free, Mo-deficient, V-containing medium. A strain (RP1.11) carrying a deletion-plus-insertion mutation in the vnfDGK region produced only dinitrogenase reductase 2.</jats:p>

• 出版日期1990-6