Studying trans-acting enzymes that target carrier protein-bound amino acids during nonribosomal peptide synthesis

Methods Enzymol. 2019;617:113-154. doi: 10.1016/bs.mie.2018.12.008. Epub 2019 Feb 11.


Nonribosomal peptide biosynthesis is a complex enzymatic assembly responsible for producing a great diversity of bioactive peptide natural products. Due to the recurring arrangement of catalytic domains within these machineries, great interest has been shown in reengineering these pathways to produce novel, designer peptide products. However, in order to realize such ambitions, it is first necessary to develop a comprehensive understanding of the selectivity, mechanisms, and structure of these complex enzymes, which in turn requires significant in vitro experiments. Within nonribosomal biosynthesis, some modifications are performed by enzymatic domains that are not linked to the main nonribosomal peptide synthetase but rather act in trans: these systems offer great potential for redesign, but in turn require detailed study. In this chapter, we present an overview of in vitro experiments that can be used to characterize examples of such trans-interacting enzymes from nonribosomal peptide biosynthesis: Cytochrome P450 monooxygenases and flavin-dependent halogenases.

Keywords: Carrier protein; Cytochrome P450; Halogenase; Nonribosomal peptide synthetase; trans-interacting enzyme.

MeSH terms

  • Amino Acids / metabolism*
  • Bacteria / enzymology*
  • Bacteria / metabolism
  • Bacterial Proteins / metabolism
  • Cytochrome P-450 Enzyme System / metabolism
  • Fungal Proteins / metabolism
  • Fungi / enzymology*
  • Fungi / metabolism
  • Models, Molecular
  • Peptide Biosynthesis, Nucleic Acid-Independent*
  • Peptide Synthases / metabolism
  • Peptides / metabolism*
  • Substrate Specificity


  • Amino Acids
  • Bacterial Proteins
  • Fungal Proteins
  • Peptides
  • Cytochrome P-450 Enzyme System
  • Peptide Synthases
  • non-ribosomal peptide synthase