Functional Exploration of Novel Enzymes for Ribosomal Peptide Modification from Uncultivated Symbionts of Marine Invertebrates

Descripción del proyecto

Descubrir productos naturales ocultos en la «materia oscura microbiana»

Dado que la mayoría de las bacterias no pueden cultivarse en el laboratorio, gran parte de la denominada «materia oscura microbiana» permanece oculta, lo que limita el descubrimiento de nuevos medicamentos y el desarrollo de biotecnologías de última generación. En el proyecto NewRiPPMaturases, que cuenta con el respaldo de las acciones Marie Skłodowska-Curie, se estudiarán los péptidos sintetizados en ribosomas y modificados postraduccionalmente (RiPP, por sus siglas en inglés). La investigación combinará la prospección bioinformática para identificar nuevos grupos de genes RiPP con la expresión heteróloga para producir los compuestos correspondientes. De este modo, se cartografiará este espacio genético aún inexplorado. Por último, mediante ensayos bioquímicos se estudiará la función que desempeñan en este proceso unas enzimas biosintéticas poco habituales, las maturasas de RiPP, cuyo conocimiento podría dar lugar a nuevas herramientas biológicas de gran utilidad.

Objetivo

Studying secondary metabolites from bacterial sources has provided us with many essential medicines and biotechnologically valuable enzymes that construct these highly complex molecules. However, only a handful of talented, chemically rich bacterial producer taxa are the source of these compounds. Identifying new talented producers has been hampered by the as-yet unculturable nature of most bacteria, thus exploring this ‘microbial dark matter’ to identify new bioactive compounds and enzymology is an outstanding challenge.

The Piel lab, in collaboration with several other research groups across several studies, has recently identified a vast number of new and chemically rich and diverse BGCs from 'Entotheonella' and Acidobacteria that are sponge and coral symbionts, respectively. These producers contain a plethora of unusual, putative biosynthetic gene clusters (BGCs) for ribosomally-synthesised post-translationally modified peptides (RiPPs). These are a largely untapped natural product superfamily, found in all domains of life, that feature unprecedented enzymology to generate highly modified and structurally complex bioactive peptide products with numerous indications. Biochemical studies into RiPPs, in particular from 'Entotheonella', has identified RiPP maturases with both previously unknown mechanisms and biotechnological applications, thus highlighting the potential of investigating RiPP pathways from microbial dark matter.

NewRiPPMaturases will explore the RiPP BGCs from 'Entotheonella' and Acidobacteria, a fraction of which have only been previously studied, to expand the repertoire of RiPP natural products and RiPP maturase biochemistry. This will be achieved using a combination of bioinformatic workflows for identifying unusual RiPP gene clusters with high confidence, characterisation of RiPP compounds produced using heterologous expression, and biochemical studies into the substrate profile and mechanism of the unusual RiPP maturases.