Experimental and computational snapshots of C-C bond formation in a C-nucleoside synthase

Journal article

The biosynthetic enzyme, ForT, catalyses the formation of a C-C bond between 4-amino-1H-pyrazoledicarboxylic acid and MgPRPP to produce a C-nucleoside precursor of formycin A. The transformation catalysed by ForT is of chemical interest because it is one of only a few examples in which C-C bond formation takes place via an electrophilic substitution of a small, aromatic heterocycle. In addition, ForT is capable of discriminating between the aminopyrazoledicarboxylic acid and an analogue in which the amine is replaced by a hydroxyl group; a remarkable feat given the steric and electronic similarities of the two molecules. Here we report biophysical measurements, structural biology and quantum chemical calculations that provide a detailed molecular picture of ForT-catalysed C-C bond formation and the conformational changes that are coupled to catalysis. Our findings set the scene for employing engineered ForT variants in the biocatalytic production of novel, anti-viral C-nucleoside and C-nucleotide analogues.

Authors: Li, W; Girt, GC; Radadiya, A; Stewart, JJP; Richards, NGJ

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: The Royal Society
• Journal: Open Biology
• Volume: 13
• Issue: 1
• Pages: 220287
• Article number: 220287
• Publication date: 2023-01-11
• Acceptance date: 2022-11-30
• DOI: 10.1098/rsob.220287
• EISSN: 2046-2441
• ISSN: 2046-2441
• Language: English
• Keywords: X-ray crystallography; formycin; biosynthesis; C-nucleoside