The Function of Two Radical‐SAM Enzymes, HcgA and HcgG, in the Biosynthesis of the [Fe]‐Hydrogenase Cofactor
Abstract
In the biosynthesis of the iron‐guanylylpyridinol (FeGP) cofactor, 6‐carboxymethyl‐5‐methyl‐4‐hydroxy‐2‐pyridinol (1) is 3‐methylated to form 2, then 4‐guanylylated to form 3, and converted into the full cofactor. HcgA‐G proteins catalyze the biosynthetic reactions. Herein, we report the function of two radical S‐adenosyl methionine enzymes, HcgA and HcgG, as uncovered by in vitro complementation experiments and the use of purified enzymes. In vitro biosynthesis using the cell extract from the Methanococcus maripaludis ΔhcgA strain was complemented with HcgA or precursors 1, 2 or 3. The results suggested that HcgA catalyzes the biosynthetic reaction that forms 1. We demonstrated the formation of 1 by HcgA using the 3 kDa cell extract filtrate as the substrate. Biosynthesis in the ΔhcgG system was recovered by HcgG but not by 3, which indicated that HcgG catalyzes the reactions after the biosynthesis of 3. The data indicated that HcgG contributes to the formation of CO and completes biosynthesis of the FeGP cofactor.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Nov 17, 2022
- Source ID
- 10.1002/ange.202213239
Entities
People
- Francisco J. Arriaza‐gallardo
- Georgia Angelidou
- Hui‐jie Pan
- Jörg Kahnt
- Kyle C Costa
- Mohd Farid Abdul‐halim
- Nicole Paczia
- Sebastian Schaupp
- Seigo Shima
- Xile Hu
- Yu‐cong Zheng
Organizations
- German Research Foundation
- Max Planck Society
- Swiss Federal Institute of Technology in Lausanne
- Swiss National Science Foundation
- United States Department of Energy
- University of Minnesota