8S02

BzdNO-benzoyl-CoA complex

Summary for 8S02

• Entry DOI: 10.2210/pdb8s02/pdb
• Descriptor: BzdO, BzdN, benzoyl coenzyme A, ... (8 entities in total)
• Functional Keywords: benzoyl-coa reductase, reductive dearomatization, iron-sulfur clusters, oxidoreductase
• Biological source: Azoarcus sp. CIB; More
• Total number of polymer chains: 4
• Total formula weight: 193946.89

Authors

Ermler, U.,Boll, M.,Fuchs, J.,Demmer, U. (deposition date: 2024-02-13, release date: 2025-03-05, Last modification date: 2025-09-17)

Primary citation

Fuchs, J.,Fernandez-Arevalo, U.,Demmer, U.,Diaz, E.,Ullmann, G.M.,Pierik, A.J.,Ermler, U.,Boll, M.
Enzymatic Birch reduction via hydrogen atom transfer at [4Fe-4S]-OH 2 and [8Fe-9S] clusters.
Nat Commun, 16:3236-3236, 2025

PubMed Abstract: The alkali metal- and ammonia-dependent Birch reduction is the classical synthetic method for achieving dihydro additions to arenes, typically yielding 1,4-cyclodienes. A mild biological alternative to this process are 1,5-dienoyl-coenzyme A (CoA)-forming class I and II benzoyl-CoA reductases (BCRs), widely abundant key enzymes in the biodegradation of aromatic compounds at anoxic environments. To obtain a comprehensive mechanistic understanding of class I BCR catalysis, we produced the active site subunits from a denitrifying bacterium and determined the X-ray structure of its substrate and product complexes at 1.4 Å revealing non-canonical double-cubane [8Fe-9S] and active site aqua-[4Fe-4S] clusters. Together with kinetic, spectroscopic and QM/MM studies, we provide evidence for a radical mechanism with a [4Fe-4S] cluster-bound water molecule acting as hydrogen atom and electron donor at potentials beyond the biological redox window. An analogous Birch-like radical mechanism is applied by class II BCRs with the catalytic water bound to a tungsten-bis-metallopterin cofactor. The use of activated, metal-bound water ligands as hydrogen atom donor serves as a basic blueprint for future enzymatic or biomimetic Birch reduction processes.

PubMed: 40185728
DOI: 10.1038/s41467-025-58418-w

Experimental method

X-RAY DIFFRACTION (1.35 Å)