title: Contiguous organization of nitrogenase genes in a heterocystous cyanobacterium.
abstract: The organization of the three structural nitrogen fixation (nif) genes that encode nitrogenase (nif K and nif D) and nitrogenase reductase (nif H) have been examined in a number of cyanobacteria. Hybridization of Anabaena 7120 nif gene probes to restriction endonuclease-digested genomic DNA has shown (a) that cyanobacteria incapable of N(2) fixation have no regions of DNA with significant homology to the three nif probes, (b) that Pseudanabaena sp., a nonheterocystous cyanobacterium, has a contiguous nif KDH gene cluster, and (c) that in contrast with other heterocystous cyanobacteria, Fischerella sp. has a contiguous nif KDH gene cluster.
authors: Department of Botany, University of Toronto, Toronto, Ontario, Canada M5S 1A1.
authors: B
authors: B
authors: Saville
authors: N
authors: N
authors: Straus
authors: J R
authors: JR
authors: Coleman