biostudies-literatureGordon MTNational Institute of General Medical SciencesNIGMS NIH HHS2095-2104https://www.ebi.ac.uk/biostudies/studies/S-EPMC12487726biostudies-literatureUnknown20(9)PKAL-1 is a fatty acyl-AMP ligase that plays an essential role in the biosynthesis of the nemamides, hybrid polyketide-nonribosomal peptides from nematodes that promote recovery from starvation-induced larval arrest. This enzyme traffics biosynthetic intermediates between two enzymatic assembly lines: the hybrid polyketide synthase-nonribosomal peptide synthetase PKS-1 and the nonribosomal peptide synthetase NRPS-1. Specifically, a <i>pkal-1</i> mutant worm strain does not produce the nemamides but accumulates a β-amino-containing polyketide, named nematide A, which is made by PKS-1 and is potentially loaded by PKAL-1 onto NRPS-1. Here, however, we show that PKAL-1 does not accept β-amino-containing substrates. Furthermore, phylogenetic and structural analyses of PKAL-1 indicate that it isACS chemical biologyCharacterizing the Biochemical Role of an Unusual Fatty Acyl-AMP Ligase from a Hybrid PKS-NRPS Pathway in Nematodes.PMC12487726R35 GM114076R35 GM144076Li XPriyaYu RGordon MTGonzalez MSAbraham EButcher RAPrajapati DVfalseCharacterizing the Biochemical Role of an Unusual Fatty Acyl-AMP Ligase from a Hybrid PKS-NRPS Pathway in Nematodes.PKAL-1 is a fatty acyl-AMP ligase that plays an essential role in the biosynthesis of the nemamides, hybrid polyketide-nonribosomal peptides from nematodes that promote recovery from starvation-induced larval arrest. This enzyme traffics biosynthetic intermediates between two enzymatic assembly lines: the hybrid polyketide synthase-nonribosomal peptide synthetase PKS-1 and the nonribosomal peptide synthetase NRPS-1. Specifically, a <i>pkal-1</i> mutant worm strain does not produce the nemamides but accumulates a β-amino-containing polyketide, named nematide A, which is made by PKS-1 and is potentially loaded by PKAL-1 onto NRPS-1. Here, however, we show that PKAL-1 does not accept β-amino-containing substrates. Furthermore, phylogenetic and structural analyses of PKAL-1 indicate that it is2025-01-01T00:00:00Z2025 Sep2026-06-04T01:55:09.879Z2026-05-04T03:14:10.981ZS-EPMC124877264081498310.1021/acschembio.5c00237