Adenosylcobinamide-phosphate synthase (, CbiB) is an enzyme with systematic name adenosylcobyric acid:(R)-1-aminopropan-2-yl phosphate ligase (ADP-forming). This enzyme catalyses the following chemical reaction
One of the substrates, (R)-1-aminopropan-2-yl phosphate, is produced by CobD (). This enzyme is part of the biosynthetic pathway to cobalamin (vitamin B<sub>12</sub>) in bacteria.