SUMMARY: Studies with a mutant of reported to be deficient in phospho-pyruvate carboxykinase activity (AB257) indicate that it possesses two mutations. One affects growth on succinate ( ), and the other primarily affects growth on fumarate and malate and affects growth on succinate to a lesser extent ( ). Neither of these mutations has a direct effect on carboxykinase activity. Presence of the mutation also prevents growth on acetate. It delays growth on other substrates such as lactate, glycerol and malate and it specifically inhibits the oxidation of succinate by mutant suspensions. The only biochemical lesion which could be detected was a deficiency in succinate dehydrogenase and it is thought that the locus may be situated in the structural gene for this enzyme. Transduction with phage P1 indicates linkages between and and of 97 and 90%, respectively and the gene order was established. The mutation was also found in the parental strain AB257. It affects the oxidation of succinate, fumarate and malate by mutant suspensions. The uptake of the dicarboxylic acids is also impaired but no other biochemical lesion could be detected. Genetic studies indicate that the mutation is located near


Article metrics loading...

Loading full text...

Full text loading...

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