title: Purine metabolism in neisseria meningitidis. 4. Interconversion of purine ribonucleotides.
abstract: Radioactive hypoxanthine and adenine were readily incorporated into the nucleic acids (RNA + DNA) of the prototrophic strain M1 of Neisseria meningitidis with labelling of the purine bases adenine and guanine. Contrary to this, adenine was incorporated into the nucleic acids with labelling of adenine only in the purine mutant 6-1c which requires adenine and guanine for growth. Guanine was in both strains incorporated into the nucleic acids with labelling of the purine base guanine only. Crude meningococcal extracts from the prototrophic strain M1 and strain 6-1b requiring histidine, proline, adenine and guanine for growth (his pro A G) were found to have activities corresponding to adenylosuccinate synthetase (EC 6.3.4.4), adenylosuccinate lyase (EC 4.3.2.2.), inosine 5'-phosphate dehydrogenase (EC 1.2.1.14)) and guanosine 5'-phosphate synthetase (EC 6.3.5.2). This last enzyme was active also with (NH4)2SO4 as amino donor. No activity corresponding to guanosine 5'-phosphate reductase (EC 1.6.6.8) could be demonstrated in either strain. The findings show that the mutant strains 6-1b and 6-1c are both blocked between aminoimidiazolcarboxamide ribonucleotide (AICA-R) and inosine 5'-phosphate (IMP). Transformation experiments with mutants requiring adenine and guanine for growth indicate that the negative property of these mutants is due to a lesion in one genetic locus or at least in loci that are very closely linked.
mesh_terms: D000225:Adenine / Q000378:metabolism; D004269:DNA, Bacterial / Q000378:metabolism; D006147:Guanine / Q000378:metabolism; D006639:Histidine / Q000378:metabolism; D007658:Ketone Oxidoreductases / Q000378:metabolism; D008025:Ligases / Q000378:metabolism; D008190:Lyases / Q000378:metabolism; D009345:Neisseria meningitidis / Q000201:enzymology / Q000378:metabolism*; D011392:Proline / Q000378:metabolism; D011685:Purine Nucleotides / Q000378:metabolism*; D012329:RNA, Bacterial / Q000378:metabolism
chemical_list: D004269:DNA, Bacterial; D011685:Purine Nucleotides; D012329:RNA, Bacterial; D006639:Histidine; D006147:Guanine; D011392:Proline; D007658:Ketone Oxidoreductases; D008190:Lyases; D008025:Ligases; D000225:Adenine