Serine residue 45 of nodulation protein NodF from Rhizobium leguminosarum bv. viciae is essential for its biological function

A system for testing the role of the Rhizobium nodF gene in the production of host-specific lipochitin oligosaccharides and in nodulation was developed. We show that a mutant nodF gene, in which the codon for serine residue 45 was changed to that for threonine, still expresses NodF, which, however, is no longer functional.