biostudies-literatureArriaza-Gallardo FJU.S. Department of EnergyInternational Max Planck Research School for Environmental, Cellular and Molecular MicrobiologyMax-Planck-Gesellschafte202213239https://www.ebi.ac.uk/biostudies/studies/S-EPMC10100467biostudies-literatureUnknown61(50)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 sysAngewandte Chemie (International ed. in English)The Function of Two Radical-SAM Enzymes, HcgA and HcgG, in the Biosynthesis of the [Fe]-Hydrogenase Cofactor.PMC10100467DE-SC0019148Zheng YCKahnt JHu XSchaupp SPan HJAbdul-Halim MFCosta KAngelidou GPaczia NShima SArriaza-Gallardo FJfalseThe Function of Two Radical-SAM Enzymes, HcgA and HcgG, in the Biosynthesis of the [Fe]-Hydrogenase Cofactor.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 sys2022-01-01T00:00:00Z2022 Dec2025-04-05T11:29:33.744Z2025-02-18T23:40:55.973ZS-EPMC101004673626400110.1002/anie.202213239