Related Experiment Video
Updated: Aug 10, 2026

Functional Complementation Analysis (FCA): A Laboratory Exercise Designed and Implemented to Supplement the Teaching of Biochemical Pathways
Published on: June 24, 2016
Structural and functional analysis of nitrogenase genes from the broad-host-range Rhizobium strain ANU240
J Badenoch-Jones1, T A Holton, C M Morrison
1Research School of Biological Sciences, Australian National University, Canberra City.
Abstract:
The genes encoding the structural components of nitrogenase, nifH, nifD and nifK, from the fast-growing, broad-host-range Rhizobium strain ANU240 have been identified and characterized. They are duplicated and linked in an operon nifHDK in both copies. Sequence analysis of the nifH gene from each copy, together with partial sequence analysis of the nifD and nifK genes, and restriction endonuclease analysis suggested that the duplication is precise. Comparison of the Fe-protein sequence from strain ANU240 with that from other nitrogen-fixing organisms revealed that, despite its broad host range and certain physiological properties characteristic of Bradyrhizobium strains, ANU240 is more closely related to the narrow-host-range Rhizobium strains than to the broad-host-range Bradyrhizobium strains. The promoter regions of both copies of the nif genes contain the consensus sequence characteristic of nif promoters, and functional analysis of the two promoters suggested that both nif operons are transcribed in nodules.
More Related Videos
Related Concept Videos
The Roles of Bacteria and Fungi in Plant Nutrition
Bacterial RNA Polymerase
In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize...
Overview of Nitrogen Metabolism
The largest pool of nitrogen available in the terrestrial ecosystem is gaseous nitrogen (N2) from the air, but this nitrogen...
Nucleoid
Inorganic Nitrogen Assimilation
Microbes and the Nitrogen Cycle

