Identification of novel L-amino acid alpha-ligases through Hidden Markov Model-based profile analysis.

L-Amino acid alpha-ligase (Lal), catalyzing the formation of alpha-dipeptides from unprotected L-amino acids in an ATP-dependent manner, is used in cost-effective fermentative production of dipeptides. We searched for novel Lals by in silico screening using Hidden Markov Model-based profile analysis, and identified five novel Lals that showed low similarity and different substrate specificity from known Lals.