# Targeted Inactivation of an α/β Hydrolase Gene Enables Discovery of Heterodimeric Nenestatins

## TL;DR

Scientists discovered new chemical compounds called NENs by inactivating a specific gene in a type of bacteria.

## Contribution

Targeted gene inactivation revealed new NEN analogs and highlighted the role of Nes5 in their biosynthesis.

## Key findings

- Inactivating the nes5 gene produced five new NEN analogs (NENs E–I) and a known compound.
- NEN A and NEN B were absent in the mutant, showing Nes5 is essential for their production.
- Structures of the new analogs were determined using spectroscopy and computational methods.

## Abstract

Nenestatins (NENs) belong to benzo[b]fluorene-containing atypical angucyclines, a structurally diverse class of microbial natural products. Bioinformatic analysis of the NEN biosynthetic gene cluster (nes BGC) from the deep-sea sediment-derived Micromonospora echinospora SCSIO 04089 implicated Nes5 as an α/β hydrolase. The targeted inactivation of the nes5 gene led to the accumulation of five new analogs, NENs E–I (1–5), together with the known monomer homo-dehydrorabelomycin E (6). Their structures were elucidated by comprehensive spectroscopic analysis and electronic circular dichroism calculations. Notably, both NEN A and NEN B were absent in the Δnes5 mutant, indicating that Nes5 is essential for their biosynthesis; however, the exact function of Nes5 requires further exploration.