2-[(2-aminoethylcarbamoyl)methyl]-2-hydroxybutanedioate + (S)-2,3-diaminopropanoate + ATP = 2-[(L-alanin-3-ylcarbamoyl)methyl]-3-(2-aminoethylcarbamoyl)-2-hydroxypropanoate + AMP + diphosphate
2-[(2-aminoethylcarbamoyl)methyl]-2-hydroxybutanedioate + (s)-2,3-diaminopropanoate + atp = 2-[(l-alanin-3-ylcarbamoyl)methyl]-3-(2-aminoethylcarbamoyl)-2-hydroxypropanoate + amp + diphosphate