Phosphoribosyl aminoimidazole succinocarboxamide

Phosphoribosyl aminoimidazole succinocarboxamide Phosphoribosyl aminoimidazole carboxamide... 

Phosphoribosyl aminoimidazole succinocarboxamide is cleaved in a reversible manner to fumarate and the well-characterized intermediate, phosphoribosyl aminoimidazole carboxamide. The enzyme catalyzing this coo-... 

Phosphoribosyl aminoimidazole succinocarboxamide synthetase Carbon-nitrogen Aspartate amino transfer Yes Yes... 

Phosphoribosyl aminoimidazole carboxylase Phosphoribosyl aminoimidazole succinocarboxamide 15 19... 

As mentioned in Chapter 7, adenylosuccinate lyase not only functions in purine ribonucleotide interconversion, but also converts phosphori-bosyl aminoimidazole succinocarboxamide to phosphoribosyl amino-imidazole carboxamide. Kinetic studies show that these compounds are alternative substrates and products, respectively, with adenylosuccinate and adenylate, and attempts physically to separate the two activities have consistently failed. Genetic studies have shown that both activities are governed by the same locus and that mutant enzymes behave similarly in both reactions 20, 21). 

This enzyme [EC 4.3.2.2], also referred to as adenylosuc-cinase, catalyzes the conversion of A -(l,2-dicarboxy-ethyl)AMP (or, adenylosuccinate) to yield fumarate and AMP. The enzyme will also convert l-(5-phosphoribo-syl)-4-(A-succinocarboxamide)-5-aminoimidazole to 5 -phosphoribosyl-5-amino-4-imidazolecarboxamide. 

Phosphoribosyl-1-pyrophosphate synthetase 2 aminophosphoribosyltransferase 3 phospho-ribosylglycinamide synthetase 4 glycinamide ribonucleotide transformylase 5 iV-formylglycin-amidine ribonucleotide amidoligase 6 5-aminoimidazole ribonucleotide synthetase 7 5-amino-imidazole ribonucleotide carboxylase 8 5-aminoimidazole-4-iV-succinocarboxamide ribonucleotide synthetase 9 adenylosuccinate lyase 10 5-aminoimidazole-4-carboxamide ribonucleotide transformylase 11 inosinicase... 

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