Plays a role in ascaroside pheromones biosynthesis, which regulates development and behavior (PubMed:29863473, PubMed:28371259, PubMed:32702987). Specifically, activates the side chain of medium-chain indol-3-carbonyl (IC)-ascarosides for shortening through beta-oxidation (PubMed:29863473, PubMed:32702987). Converts IC-asc-C7 and IC-asc-C9 into IC-asc-C7-CoA and IC-asc-C9-CoA, respectively (PubMed:29863473, PubMed:32702987). May play a role in fatty-acid metabolism by activating and converting nonanoate (C9) into nonanoyl-CoA (C9-CoA) (PubMed:29863473). ATP + CoA + nonanoate = AMP + diphosphate + nonanoyl-CoA ATP + CoA + IC-asc-C7 = AMP + diphosphate + IC-asc-C7-CoA ATP + CoA + IC-asc-C9 = AMP + diphosphate + IC-asc-C9-CoA kcat is 0.53 sec(-1) with IC-asc-C9 (at pH 7.4 and 22 degrees Celsius). Expressed in intestine. Belongs to the ATP-dependent AMP-binding enzyme family.