Over the past 25 years, ribosomally synthesized and posttranslationally modified peptides (RiPPs) have proven to be a major class of natural products, whose expanding breadth of unique structures and bioactivities are beginning to rival those of non-ribosomal peptides. Initially translated by the ribosome, RiPPs are typically synthesized as short precursor peptides that are extensively posttranslationally modified at their C-termini prior to proteolytic maturation and export. The short N-terminal leader peptides of RiPP precursors serve as docking domains that direct an assortment of tailoring enzymes to install post-translational modifications (PTMs) on the C-terminal core peptide destined to become the mature natural product. In prokaryotes, RiPPs are often encoded in monocistronic, streamlined biosynthetic gene clusters where encoded tailoring enzymes frequently introduce multiple modifications in a given RiPP precursor. Peptide backbone α-N-methylations change the physicochemical properties of amide bonds to provide structural constraints and other favorable characteristics including biological membrane permeability to peptides. Borosin natural product pathways are the only known ribosomally encoded and posttranslationally modified peptides (RiPPs) pathways to incorporate backbone α-N-methylations on translated peptides. Here you can see the crystal structure of a borosin methyltransferase from Mycena rosella, showing the tight packing of the enzyme dimer (PDB code: 7TWL)
#molecularart ... #immolecular ... #RiPPs ... #peptide ... #methylation ... #borosin ... #xray
Structure rendered with @proteinimaging and depicted with @corelphotopaint
#molecularart ... #immolecular ... #RiPPs ... #peptide ... #methylation ... #borosin ... #xray
Structure rendered with @proteinimaging and depicted with @corelphotopaint
