title: Biosynthesis of vitamin B-12. Part I. Role of the ribosomal proteins in vitamin B-12 biosynthesis.
abstract: 1. 70 S ribosomes isolated from strains of Escherichia coli 113-3, K12 and B take part in vitamin B-12 biosynthesis from AdoCbi-GDP, NAD and dimethylbenzimidazole in the presence of enzymes of the cytosol fraction. 2. 70 S ribosomes from E.coli 113-3 bind Ado[58Co]Cbi-GDP. This reaction is independent of fusidic acid. 3. Proteins from 5 S RNA complex as well as l3 protein isolated from E.coli 113-3 ribosomes catalyze vitamin B-12 biosynthesis. The main catalytic function in this reaction is preformed by protein L18. 4. Vitamin B-12 biosynthesis proceeding in the presence of isolated ribosomal proteins is inhibited by fusidic acid, chloramphenicol and vernamycin but not by erythromycin. 5. Vitamin B-12 synthesized in the presence of isolated ribosomal proteins is biologically active.
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000378:metabolism*; D003038:Cobamides / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism*; D046911:Macromolecular Substances; D008954:Models, Biological; D012335:RNA, Ribosomal / Q000494:pharmacology; D012260:Ribonucleases / Q000378:metabolism; D012269:Ribosomal Proteins / Q000302:isolation & purification / Q000378:metabolism*; D012270:Ribosomes / Q000378:metabolism; D013045:Species Specificity; D014805:Vitamin B 12 / Q000096:biosynthesis*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D003038:Cobamides; D046911:Macromolecular Substances; D012335:RNA, Ribosomal; D012269:Ribosomal Proteins; C033344:cobamamide 5'-phosphate; D012260:Ribonucleases; D014805:Vitamin B 12