similar to adenylation domain of cytotrienin synthetase CytC1
This family of the adenylation (A) domain of nonribosomal peptide synthases (NRPS) includes Streptomyces sp. cytotrienin synthetase (CytC1), a relatively promiscuous adenylation enzyme that installs the aminoacyl moieties on the phosphopantetheinyl arm of the holo carrier protein CytC2. Also included are Streptomyces sp Thr1, involved in the biosynthesis of 4-chlorothreonine, Pseudomonas aeruginosa pyoverdine synthetase D (PvdD), involved in the biosynthesis of the siderophore pyoverdine and Pseudomonas syringae syringopeptin synthetase, where syringpeptin is a necrosis-inducing phytotoxin that functions as a virulence determinant in the plant-pathogen interaction. The adenylation (A) domain of NRPS recognizes a specific amino acid or hydroxy acid and activates it as an (amino) acyl adenylate by hydrolysis of ATP. The activated acyl moiety then forms a thioester bond to the enzyme-bound cofactor phosphopantetheine of a peptidyl carrier protein domain. NRPSs are large multifunctional enzymes which synthesize many therapeutically useful peptides in bacteria and fungi via a template-directed, nucleic acid independent nonribosomal mechanism. These natural products include antibiotics, immunosuppressants, plant and animal toxins, and enzyme inhibitors. NRPS has a distinct modular structure in which each module is responsible for the recognition, activation, and in some cases, modification of a single amino acid residue of the final peptide product. The modules can be subdivided into domains that catalyze specific biochemical reactions.
Jiyao W et al.(2023). "The conserved domain database in 2023.",