Catalysis of the lipoylation of a protein in two steps: ATP + (R)-lipoate + a -L-lysine = a -N6-(lipoyl)lysine + AMP + diphosphate (overall reaction): (1) ATP + (R)-lipoate = lipoyl-AMP + diphosphate; (2) lipoyl-AMP + a -L-lysine = a -N6-(lipoyl)lysine + AMP.
lipoate-protein ligase B activity