similar to adenylation domain of chondramide synthase cmdD
This family of the adenylation (A) domain of nonribosomal peptide synthases (NRPS) includes phosphinothricin tripeptide (PTT, phosphinothricylalanylalanine) synthetase, where PTT is a natural-product antibiotic and potent herbicide that is produced by Streptomyces hygroscopicus. This adenylation domain has been confirmed to directly activate beta-tyrosine, and fluorinated chondramides are produced through precursor-directed biosynthesis. Also included in this family is chondramide synthase D (also known as ATP-dependent phenylalanine adenylase or phenylalanine activase or tyrosine activase). Chondramides A-D are depsipeptide antitumor and antifungal antibiotics produced by C. crocatus, are a class of mixed peptide/polyketide depsipeptides comprised of three amino acids (alanine, N-methyltryptophan, plus the unusual amino acid beta-tyrosine or alpha-methoxy-beta-tyrosine) and a polyketide chain ([E]-7-hydroxy-2,4,6-trimethyloct-4-enoic acid).