If you have an ACS member number, please enter it here so we can link this account to your membership. (optional)

ACS values your privacy. By submitting your information, you are gaining access to C&EN and subscribing to our weekly newsletter. We use the information you provide to make your reading experience better, and we will never sell your data to third party members.



Marine microbial dehalogenase removes unwanted bromine

Extra bromine needs to go before final coupling reaction in the biosynthesis of pentabromopseudilin

by Celia Henry Arnaud
October 17, 2016 | A version of this story appeared in Volume 94, Issue 41

Although the marine natural product pentabromopseudilin was first characterized 50 years ago, its biosynthesis is still not completely understood. Researchers at the University of California, San Diego, have now determined that, in addition to enzymes for adding bromines to the molecule, the biosynthetic pathway for pentabromopseudilin also includes an enzyme for removing bromine (J. Am. Chem. Soc. 2016, DOI: 10.1021/jacs.6b08512). A set of enzymes in the pathway catalyzes the synthesis of the needed precursors. But one of those precursors has one too many bromines. The enzymes make 2,3,4,5-tetrabromopyrrole when what’s really needed is 2,3,4-tribromopyrrole. Bradley S. Moore and coworkers have identified Bmp8 as the enzyme responsible for the required dehalogenation. After Bmp8 removes the unwanted bromine via a redox thiol mechanism involving a specific cysteine residue, another enzyme couples the tribromopyrrole to 2,4-dibromophenol to form pentabromopseudilin. The enzymatic dehalogenation of man-made persistent organic pollutants is well-known, but to the best of the researchers’ knowledge, Bmp8 is the first example of a marine microbial dehalogenase that’s involved in the biosynthesis of a halogenated natural product.

A reaction scheme shows the biosynthesis of pentabromopseudilin.
Enzymes add and subtract bromine in this segment of a bacterial metabolic pathway.


This article has been sent to the following recipient:

Chemistry matters. Join us to get the news you need.