What is the role of hypoxanthine-guanine phosphoribosyltransferase?
The enzyme hypoxanthine-guanine phosphoribosyltransferase (HGPRT) is one of the central enzymes that recycle the building blocks of RNA and DNA. It attaches a purine base (either guanine or hypoxanthine, a modified form of adenine) to a sugar, creating a nucleotide.
What reaction is catalysed by Phosphoribosyltransferase?
Hypoxanthine-guanine phosphoribosyltransferase (HGPRTase) catalyzes the reversible formation of IMP and GMP from their respective bases hypoxanthine (Hx) and guanine (Gua) and the phosphoribosyl donor 5-phosphoribosyl-1-pyrophosphate (PRPP).
What does HPRT1 code for?
a number of HPRT mutations in Asian patients manifesting different clinical phenotypes.
What is the final product of purine catabolism?
Uric acid is the end product of purine metabolism in humans. Two-thirds of uric acid in the human body is normally excreted through the kidney, whereas one-third undergoes uricolysis (decomposition of uric acid) in the gut.
What is the role of phosphoribosyl pyrophosphate synthetase?
Phosphoribosyl-pyrophosphate synthetase (Prs) catalyses the synthesis of phosphoribosyl pyrophosphate (PRPP), an intermediate in nucleotide metabolism and the biosynthesis of the amino acids histidine and tryptophan.
What enzyme makes PRPP?
Phosphoribosyl pyrophosphate (PRPP) is a pentosephosphate. It is formed from ribose 5-phosphate by the enzyme ribose-phosphate diphosphokinase. In de novo generation of purines, the enzyme amidophosphoribosyltransferase acts upon PRPP to create phosphoribosylamine.
Why is HPRT used as a control?
HPRT is a housekeeping enzyme involved in recycling guanine and inosine in the purine salvage pathway. As a housekeeping gene, HPRT has been widely used as an endogenous control for molecular studies evaluating changes in gene expression.
What is hypoxanthine in fish?
Hypoxanthine is regarded as the major catabolite of adenosine triphosphate (ATP) and it is a useful indicator of freshness because of its gradual accumulation in seafood. Hx value rapidly increases in ice storage and the content of the muscle is used for the determination of the post-mortem age in seafood.
What does hypoxanthine bind?
Hypoxanthine pairs with cytosine rather than with thymine (Figure 27.43). Uracil pairs with adenine rather than with guanine. Xanthine, like guanine, pairs with cytosine.
What is the role of hypoxanthine-guanine phosphoribosyltransferase in RNA and DNA?
Purine Salvage. The enzyme hypoxanthine-guanine phosphoribosyltransferase (HGPRT) is one of the central enzymes that recycle the building blocks of RNA and DNA. It attaches a purine base (either guanine or hypoxanthine, a modified form of adenine) to a sugar, creating a nucleotide.
What are the side effects of hypoxanthine phosphoribosyltransferase?
Physiologically, there is typically hyperuricemia and uricosuria, which may lead to gouty arthritis, tophus formation, hematuria, kidney stones, urinary tract infection, and renal failure. There is a spectrum of disease, reflective of the activity of HPRT, and, in this disorder, the erythrocyte activity is essentially undetectable.
Which is the enzyme that attaches guanine to a sugar?
The enzyme hypoxanthine-guanine phosphoribosyltransferase (HGPRT) is one of the central enzymes that recycle the building blocks of RNA and DNA. It attaches a purine base (either guanine or hypoxanthine, a modified form of adenine) to a sugar, creating a nucleotide.
Which is enzyme recycles guanine to guanosine monophosphate?
Hypoxanthine phosphoribosyltransferase is a human enzyme involved in the purine salvage pathway. It recycles guanine to guanosine monophosphate during DNA degradation. It is encoded by the human HPRT1 gene and has been widely studied since the 1960s.