Involved in dapdiamide antibiotics biosynthesis (PubMed:19807062, PubMed:20945916). Ligates N-beta-fumaramoyl-DAP and valine, isoleucine or leucine to form dapdiamides A, B or C, respectively (PubMed:19807062). Also ligates N-beta-epoxysuccinamoyl-DAP and valine to form dapdiamide E (PubMed:20945916). 3-[[[(2R,3R)-3-carboxyoxiran-2-yl]carbonyl]amino]-L-alanine + ATP + L-valine = ADP + dapdiamide E + H(+) + phosphate ATP + L-valine + N(3)-fumaramoyl-(S)-2,3-diaminopropanoate = ADP + dapdiamide A + H(+) + phosphate ATP + L-isoleucine + N(3)-fumaramoyl-(S)-2,3-diaminopropanoate = ADP + dapdiamide B + H(+) + phosphate ATP + L-leucine + N(3)-fumaramoyl-(S)-2,3-diaminopropanoate = ADP + dapdiamide C + H(+) + phosphate Binds 1 magnesium or manganese ion per subunit. kcat is 8.1 min(-1) with valine as substrate. kcat is 9.5 min(-1) with isoleucine as substrate. kcat is 11.2 min(-1) with leucine as substrate (PubMed:19807062). kcat is 21 min(-1) with N-beta-fumaramoyl-DAP as substrate. kcat is 181 min(-1) with N-beta-epoxysuccinamoyl-DAP as substrate (PubMed:20945916). Antibiotic biosynthesis.