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Abstract

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  2. Abstract
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The pur R gene encodes a repressor (PurR) controlling the synthesis of the enzymes of purine biosynthesis. The subunit of PurR was identified as a 38-kDa polypeptide by SDS/polyacrylamide gel electrophoresis. Analysis of a pur R–lacZ transcriptional fusion indicated that pur R expression is autoregulated. This was confirmed by gel retardation and DNasel footprinting experiments, where two PurR-binding sites were identified in the transcribed part of pur R. Introduction of a purR mutation in wild-type and pur – lac fusion strains was found to abolish purine repression of all genes of the purine biosynthetic pathway except for pur A.

Enzymes
 

Amidophosphoribosyltransferase (EC 2.4.2.14)

 

phosphoribosylglydinamide synthetase (EC 6.3.4.13)

 

adenylosuccinate synthetase (EC 6.3.4.4)

 

adenylosuccinate lyase (EC 4.3.2.2)

 

IMP dehydrogenase (EC 1.1.1.205)

 

GMP synthetase (EC 6.3.4.1)

REFERENCES

  1. Top of page
  2. Abstract
  3. REFERENCES