Expression of 9 Salmonella typhimurium enzymes for cobinamide synthesis Identification of the 11-methyl and 20-methyl transferases of corrin biosynthesis

• Published in: FEBS letters 1992-04, Vol.301 (1), p.73-78
• Main Authors: Roessner, Charles A., Warren, Martin J., Santander, Patricio J., Atshaves, Barbara P., Ozaki, Shin-ichi, Stolowich, Neal J., Iida, Katsumi, Scott, A.Ian
• Format: Article
• Language: English
• Subjects: 13C-NMR; 5-aminolevulinic acid; ALA; Amino Acid Sequence; Bacterial Proteins - genetics; Bacterial Proteins - isolation & purification; Cloning, Molecular; Corrin biosynthesis; Escherichia coli - genetics; Genes, Bacterial - genetics; Magnetic Resonance Spectroscopy; Methyltransferases - biosynthesis; Methyltransferases - genetics; Molecular Sequence Data; NMR; nuclear magnetic resonance; PBG; porphobilinogen; Precorrin methyltransferase; S-adenosylmethionine; S-Adenosylmethionine - metabolism; Salmonella typhimurium; Salmonella typhimurium - enzymology; Salmonella typhimurium - genetics; SAM; SDS-PAGE; sodium dodecylsulfate polyacrylamide gel electrophoresis; Uroporphyrins - metabolism; Vitamin B 12 - biosynthesis
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/0014-5793(92)80213-Z

Nine of the cbi genes from the 17.5 kb cob operon of Salmonella typhimurium previously shown by genetic studies to be involved in the biosynthesis of cobinamide from precorrin-2, have been subcloned and expressed in Escherichia coli. Seven of the gene products were found in the soluble fraction of cell lysates and have been purified. The gene products corresponding to cbi E, F, H and L were shown by SAM binding and by homology with other SAM-binding proteins to be candidates for the methyltransferases of vitamin B 12 biosynthesis. The enzymatic functions of the gene products of cbiL and cbiF are associated with C-methylation at C-20 of precorrin-2 and C-11 of precorrin-3.