[Purine regulon of gamma-proteobacteria: a detailed description].
The structure of the purine regulon was studied by a comparative genomic approach in seven genomes of gamma-proteobacteria: Escherichia coli, Salmonella typhi, Yersinia pestis, Haemophilus influenzae, Pasteurella multocida, Actinobacillus actinomycetemcomitans, and Vibrio cholerae. The palindromic binding site of the purine repressor (consensus ACGCAAACGTTTGCGT) is fairly well retained of genes encoding enzymes that participate in the synthesis of inosinemonophosphate from phosphoribozylpyrophosphate and in transfer of unicarbon groups, and also upstream of some transport protein genes. These genes may be regarded as the main part of the purine regulon. In terms of physiology, the regulation of the purC and gcvTHP/folD genes seems to be especially important, because the PurR site was found upstream of nonorthologous but functionally replaceable genes. However, the PurR site is poorly retained in front of orthologs of some genes belonging to the E. coli purine regulon, such as genes involved in general nitrogen metabolism, biosynthesis of pyrimidines, and synthesis of AMP and GMP from IMP, and also upstream of the purine repressor gene. It is predicted that purine regulons of the examined bacteria include the following genes: upp participating in synthesis of pyrimidines; uraA encoding an uracil transporter gene; serA involved in serine biosynthesis; folD responsible for the conversion of N5,N10-methenyl tetrahydrofolate into N10-formyltetrahydrofolate; rpiA involved in ribose metabolism; and protein genes with an unknown function (yhhQ and ydiK). The PurR site was shown to have different structure in different genomes. Thus, the tendency for a decline of the conservatism of site positions 2 and 15 was observed in genomes of bacteria belonging to the Pasteurellaceae and Vibrionaceae groups.
Ravcheev
D A
DA
State Research Institute of Genetics and Selection of Industrial Microorganisms, Moscow, 113545 Russia.
Gel'fand
M S
MS
Mironov
A A
AA
Rakhmaninova
A B
AB
D000249:Adenosine Monophosphate / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D002237:Carbohydrate Dehydrogenases / Q000235:genetics / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000235:genetics; D020563:Gammaproteobacteria / Q000235:genetics* / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D023281:Genomics / Q000379:methods; D006157:Guanosine Monophosphate / Q000378:metabolism; D007291:Inosine Monophosphate / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000235:genetics; D010453:Peptide Synthases; D050543:Phosphoglycerate Dehydrogenase; D011687:Purines; D011743:Pyrimidines / Q000096:biosynthesis; D018085:Regulon; D012097:Repressor Proteins / Q000235:genetics*; D012694:Serine / Q000096:biosynthesis; D013763:Tetrahydrofolates / Q000378:metabolism
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D026901:Membrane Transport Proteins; C065825:PurR protein, Bacteria; C489317:PurR protein, E coli; D011687:Purines; D011743:Pyrimidines; D012097:Repressor Proteins; D013763:Tetrahydrofolates; C093118:UraA protein, E coli; D007291:Inosine Monophosphate; D000249:Adenosine Monophosphate; C030371:5,6,7,8-tetrahydrofolic acid; D012694:Serine; D006157:Guanosine Monophosphate; D002237:Carbohydrate Dehydrogenases; D050543:Phosphoglycerate Dehydrogenase; D010453:Peptide Synthases; C083513:PurC protein, Bacteria; C030986:pyrimidine; C030985:purine