Flavin-dependent decarboxylation of cysteine residues
Speaker: Thomas Kupke (University of Heidelberg)
Host: Heike Brötz-Oesterhelt
Date & Time: 18.07.2024 | 12:30 – 2 p.m.
Venue: Lecture hall 3M07, GUZ
Public event. No registration needed.
Abstract:
The story of “Flavin-dependent decarboxylation of cysteine residues” starts in 1985 with the structure elucidation of epidermin, the first characterized ribosomally synthesized and post-translationally modified peptide (RiPP) containing an aminovinyl-cysteine residue (AviCys). 30 years ago, it was then shown that the flavoprotein EpiD is involved in AviCys biosynthesis and catalyzes the oxidative decarboxylation of the epidermin precursor peptide EpiA (a peptidyl-cysteine) to a peptidyl-amino-enethiol.
The novel flavin binding mode of EpiD is associated with the PASANTI sequence motif. This talk summarizes the function, structure and reaction mechanism of various enzymes belonging to the new PASANTI flavoprotein superfamily. Another prominent member of this flavoprotein family is CoaC, an enzyme catalyzing the key step in coenzyme A biosynthesis, the decarboxylation of 4´-phosphopantothenoylcysteine to 4´-phosphopantetheine.
In addition, the current importance of the topic is reported: a) structure, biosynthesis and biological activity of recently discovered AviCys peptides (thioamitides, lipolanthines, linaridins …), b) genomic mining of at least hundreds new AviCys peptides, c) association of radical chemistry with LanD flavoprotein activity and formation of S-[2-aminovinyl]-3-carbamoylcysteine (AviCamCys), d) enzymatic generation of thioaldehyde motifs for peptide bioconjugation, e) prenylated flavin cofactor and ubiquinone biosynthesis, and f) inherited disorders of coenzyme A biosynthesis.