This group of proteins contains an AMP-binding domain (pfam00501) associated with acyl CoA-ligases. These proteins are generally found in genomes containing the exosortase/PEP-CTERM protein expoert system, specifically the type 1 variant of this system described by the Genome Property GenProp0652. When found in this context they are invariably present next to a decarboxylase enzyme. A number of sequences from Burkholderia species also hit this model, but the genomic context is obviously different. The hypothesis of a constant substrate for this family is only strong where the exosortase context is present.
Jiyao W et al.(2023). "The conserved domain database in 2023.",