Dual substrate‐controlled kinase activity leads to polyphosphorylated lasso peptides

Abstract

Edited by Alfonso ValenciaLasso peptides are characterized by their peculiar lariat knot-like structure. Except for maturation of this fold, post-translational modifications of lasso peptides are rare. However, we recently delineated the biosynthetic pathway of a post-translationally phosphorylated lasso peptide, paeninodin. In this study, further investigation of two kinases revealed their ability to transfer multiple phosphate groups onto precursor peptide substrates, ultimately leading to polyphosphorylated lasso peptides. We found that this polyphosphorylating activity depended on the identity of the phosphate donor and the sequence of the precursor peptide. Our investigations provide new insight into the remarkable strategies for chemical diversification employed by the lasso peptide biosynthetic machinery.

Transcription-factor centric genome mining strategy for discovery of diverse unprecedented RiPP gene clusters

“…Past research has shown that bioinformatics studies could readily identify novel RiPPs using homology searching methods [15]. For example, novel modified lasso peptides, such as phosphorylated and acetylated lasso peptides, were discovered using this strategy [24][25][26]. However, completely new families of RiPPs have not been discovered by these strategies, which hinders the progress of RiPP research.…”

The B1 Protein Guides the Biosynthesis of a Lasso Peptide

“…Another recently identified series of proteobacterial lasso peptides, including astexin-1, sphingopyxin I, and caulosegnin I, are synthesized from gene clusters that feature a lasso peptide-specific isopeptidase instead of an ABC transporter 12 15 18 19 33 34 35 36 37 . Yet another putative, proteobacterial gene cluster features a lasso peptide-tailoring kinase (K) with A B1 B2 C K D organization 19 24 38 . Here, the “split” B1 and B2 proteins share homology with the N- and C-terminal domains of an “intact” B protein, respectively.…”

“…Split B proteins were also observed in actinobacterial clusters such as those producing lariatin, sviceucin, and streptomonomicin (A C B1 B2 D organization) as well as firmicute clusters (C A K B1 B2 D organization) such as that of paeninodin 11 13 39 40 . Kinases from the latter were recently characterized as tailoring enzymes of lasso peptide precursors, ultimately yielding phosphorylated lasso peptides 24 38 . A general schematic for the proposed route of lasso peptide biosynthesis is presented in Fig.…”

Efficient in vivo synthesis of lasso peptide pseudomycoidin proceeds in the absence of both the leader and the leader peptidase

“…The predicted sequence of PsmA ends with an asparagine residue as opposed to C-terminal serine of paeninodin precursor PadeA, which is subject to phosphorylation. 14,17 We resequenced the psmA gene and found a single nucleotide difference with the published sequence at the last codon. The correct sequence in fact codes for a PsmA peptide with a terminal serine.…”