Summary: The mutant R plasmid pTH10 was used to construct a circular linkage map of the B10 chromosome. Mutations affecting nitrogen fixation ( mutations) were dispersed in several groups on the chromosome. Biochemical analysis of mutants allowed identification of the structural gene for the nitrogenase component II or Fe protein () and a putative regulatory gene, possibly . These two genes appeared closely linked in conjugation experiments, but represented two distinct linkage groups in crosses mediated by gene transfer agent. Other mutants were affected in the synthesis and/or stability of the nitrogenase component I or MoFe protein; synthesis of component II was also affected, but to a lesser extent. In two of these mutants, nitrogenase activity and the content of component I was increased five- to sixfold by the addition of 1 m-molybdate to the growth medium.


Article metrics loading...

Loading full text...

Full text loading...


Most cited this month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error