Nucleotide sequence and mutagenesis of the nifA gene from Azotobacter vinelandii |
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Authors: | L T Bennett F Cannon D R Dean |
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Institution: | Department of Anaerobic Microbiology, Virginia Polytechnic Institute and State University, Blacksburg 24061. |
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Abstract: | The nucleotide sequence of the nifA gene from Azotobacter vinelandii was determined. This gene encodes an Mr = 58,100 polypeptide that shares significant sequence identity when compared to nifA-encoded products from other organisms. Interspecies comparisons of nifA-encoded products reveal that they all have a consensus ATP binding site and a consensus DNA binding site in highly conserved regions of the respective polypeptides. The nifA gene immediately precedes the nifB-nifQ gene region but is unlinked to the major nif gene cluster from A. vinelandii. A potential regulatory gene precedes and is apparently cotranscribed with nifA. Mutant strains that have a deletion or a deletion plus an insertion within nifA are incapable of diazotrophic growth and they fail to accumulate nitrogenase structural gene products. |
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