Aminoacyl-S-enzyme intermediates in β-hydroxylations and α,β-desaturations of amino acids in peptide antibiotics

Many of the alpha -amino acids found in proteins are shunted into microbial secondary metabolism to form peptide antibiotics by specific oxidation, including hydroxylation, at the beta carbon. Examples for the enzymatic hydroxylation of tyrosine and histidine and for desaturation of proline during covalent attachment as aminoacyl-S-pantetheinyl enzyme intermediates suggest a general strategy in peptide antibiotic biosynthesis.