The Escherichia coli cysG gene encodes the multifunctional protein, siroheme synthase

• Published in: FEBS letters Vol. 335; no. 1; pp. 57 - 60
• Main Authors: Spencer, Jonathan B., Stolowich, Neal J., Roessner, Charles A., Scott, A.Ian
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 29.11.1993; Elsevier
• Subjects: Amino Acid Sequence; Analytical, structural and metabolic biochemistry; Binding Sites; Biological and medical sciences; Dehydrogenase; Enzymes and enzyme inhibitors; Escherichia coli - enzymology; Escherichia coli - genetics; Ferrochelatase; Fundamental and applied biological sciences. Psychology; Genes, Bacterial; Heme - analogs & derivatives; Heme - biosynthesis; Magnetic Resonance Spectroscopy; Methylation; Methyltransferases - chemistry; Methyltransferases - genetics; Methyltransferases - metabolism; Miscellaneous; Molecular Sequence Data; Multienzyme Complexes - chemistry; Multienzyme Complexes - genetics; Multienzyme Complexes - metabolism; NAD; NAD - metabolism; NAD - pharmacology; Sequence Homology, Amino Acid; Siroheme; Sirohydrochlorin; Uroporphyrinogens - metabolism; NAD; Sirohydrochlorin; Dehydrogenase; Ferrochelatase; Siroheme; Proteins; Gene; Enzyme; Escherichia coli; Iron II; Bacteria; Lyases; Biosynthesis; Enterobacteriaceae
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/0014-5793(93)80438-Z

Previously, the E. coli cysG gene product had been shown to sequentially methylate uro'gen III to produce precorrin-2, hence it was given the trivial name uro'gen III methylase. We now report that in addition to methylase activity, the CysG protein catalyses both the NAD + dependent oxidation of precorrin-2 to sirohydrochlorin, but also the insertion of iron into this oxidized intermediate, thereby producing siroheme. Thus CysG is a multifunctional protein solely responsible for siroheme synthesis from uro'gen III in E. coli, and accordingly is renamed siroheme synthase.