coli by chemical transformation or by electroporation. An engineered gene cluster, placed inside a gene delivery system (plasmid), is transformed into E. In one embodiment, astexin peptides are made following the basic schema of heterologous protein expression. It is the first described lasso isopeptide hydrolase.Īstexin peptides and At圎2 polypeptides can be produced using methods known in the art. At圎2 has been found to selectively cleave astexin-2 and astexin-3 peptides. Unless indicated otherwise, reference to an astexin peptide is understood to refer to an astexin-1, astexin-2 and/or an astexin-3 peptide.Īlso provided by the invention is a lasso isopeptide hydrolase, named At圎2. Astexin-3 has natural tryptophan fluorescence, which facilitates monitoring of this molecule during in vitro assays. Their natural amino acid sequences are highly polar, which stands in contrast to the hydrophobic composition of other members of its class. Astexins-2 and -3 are identical in length and are the largest molecules in the lasso peptide family. The solution structure of astexin-1 was determined, revealing a unique topology that is stabilized by hydrogen bonding between segments of the peptide.Īstexins-2 and -3 are intracellular lasso peptides that are not exported into the extracellular medium like astexin-1. Astexin-1 has modest antimicrobial activity against Caulobacter crescentus, a bacterium related to Asticaccaulis excentricus. It is also highly polar, in contrast to many lasso peptides that are primarily hydrophobic. Molecules of this class are highly stable and engineerable and are therefore attractive as molecular scaffolds.Īstexin-1 is among the largest lasso peptide isolated to date. The peptides are single lasso peptides predicted to be produced by the freshwater bacterium Asticaccaulis excentricus. The invention provides astexin polynucleotides that encode astexin peptides-astexin-1, astexin-2 and astexin-3, as well as the peptides encoded by these polynucleotides. Molecules of this class are highly stable, engineerable, and, therefore, attractive as molecular scaffolds. The invention provides a family of low molecular weight lasso peptides termed astexin-1, astexin-2, and astexin-3 (collectively, “astexin peptides”), which were are derived from a bacterial source. The characteristic threaded lasso structure in these peptides derives from an isopeptide bond attaching the N-terminus of the peptide to an acidic sidechain. Lasso peptides are a class of ribosomally-derived natural products with diverse bioactivities. 2, 2017, is named SecondCorrectedSequenceListing.txt and is 22,022 bytes in size. The instant application contains a Sequence Listing which has been submitted electronically in ASCII format and is hereby incorporated by reference in its entirety.
0 kommentar(er)
