Biochemical characterization of mutant propionyl CoA carboxylases from two minor genetic complementation groups.

We have biochemically characterized several parameters of propionyl CoA carboxylase (PCC) activity in fibroblast extracts from PCC-deficient patients belonging to the two minor genetic complementation groups with those of the two major complementation pccB and pccBC. Comparison of PCC's from these groups with those of the two major complementation groups, pcc A and pcc C, has demonstrated that PCCs from both the pcc B and pcc BC groups closely resemble each other as well as PCC from the pcc C group. These results further support the hypothesis that the pcc B and pcc BC lines are interallelic with respect to pcc C and consequently that the structural mutations in the PCCs from these groups involve the same subunit.