Required for both de novo synthesis of the corrin ring for the assimilation of exogenous corrinoids. Participates in the adenosylation of a variety of incomplete and complete corrinoids (By similarity). 2 ATP + 2 cob(II)yrinate a,c diamide + reduced [electron-transfer flavoprotein] = 2 adenosylcob(III)yrinate a,c-diamide + 3 H(+) + oxidized [electron-transfer flavoprotein] + 2 triphosphate 2 ATP + 2 cob(II)alamin + reduced [electron-transfer flavoprotein] = 2 adenosylcob(III)alamin + 3 H(+) + oxidized [electron-transfer flavoprotein] + 2 triphosphate Cofactor biosynthesis; adenosylcobalamin biosynthesis; adenosylcobalamin from cob(II)yrinate a,c-diamide: step 2/7. Monomer. Belongs to the Cob(I)alamin adenosyltransferase family. Was originally thought to originate from Pseudomonas denitrificans, but similarity searches show that the sequence is much closer to Sinorhizobium. The entry's taxonomy has been changed.