This family consists of various cobyrinic acid a,c-diamide synthases. These include CbiA and CbiP from S.typhimurium, and CobQ from R. capsulatus. These amidases catalyze amidations to various side chains of hydrogenobyrinic acid or cobyrinic acid a,c-diamide in the biosynthesis of cobalamin (vitamin B12) from uroporphyrinogen III. Vitamin B12 is an important cofactor and an essential nutrient for many plants and animals and is primarily produced by bacteria. The family also contains dethiobiotin synthetases as well as the plasmid partitioning proteins of the MinD/ParA family.