Glycerate-3-phosphate kinase

Mertens E, Van Schaftingen E, Muller M (1992) Pyruvate kinase from Trichomonas vaginalis, an allosteric enzyme stimulated by ribose 5-phosphate and glycerate 3-phos-phate. Mol Biochem Parasitol 54 13-20... 

Dihydroxyacetone phosphate is converted to glycer-aldehyde 3-phosphate by the glycolytic enzyme triose phosphate isomerase. Glyeeraldehyde is phosphorylated by ATP and triose kinase to glyeeraldehyde 3-phos-phate ... 

In the second step leading to glycerate-3-phosphate, a phosphate group is transferred from glycerate-1,3-bisphos-phate to ADP. This reaction is catalyzed by 3-phosphoglyc-erate kinase. 

In the two steps catalyzed by 3-phosphoglyceraldehyde dehydrogenase and 3-phosphoglycerate kinase, the oxidation of glyceraldehyde-3-phosphate to glycerate-3-phosphate is coupled to the regeneration of ATP. 

H+ + Glycerate-1,3-bisphosphate + ADP, Glycerate-3-phosphate + ATP 3-Phosphoglycerate kinase -4.5 +.31... 

Like all anhydrides (Section 21.5), the mixed carboxylic-phosphoric anhydride is a reactive substrate in nucleophilic acyl (or phosphoryl) substitution reactions. Reaction of 1,3-bisphosphoglycerate with, ADP occurs in step 7 by substitution on phosphorus, resulting in transfer of a phosphate group to, ADP and giving ATP plus 3-phosphoglycerate. T he process is catalyzed by phospho-glycerate kinase and requires Mg " " as cofactor. Together, steps 6 and 7 accomplish the oxidation of an aldehyde to a carboxylic acid. 

The next step is the transfer of phosphate from 1,3-bisphospho-glycerate to ADR making ATR catalyzed by phosphoglycerate kinase. 

Fig. 6.1 Reaction scheme of the system under study. Glc, glucose HK, hexokinase PGI, phos-phoglucose isomerase PFK, phosphofructokinase ALD, aldolase TIM, triose phosphate isomerase G3PDH, glycerol 3-phosphate dehydrogenase 1,3BPG 1,3-bisphosphoglycerate PGK, phospho-glycerate kinase G6P, glucose 6-phosphate F6P, fructose 6-phosphate ATP, adenosine triphosphate ADP, adenosine diphosphate PEP, phospho-enolpyruvate F1,6BP, fructose 1,6-bisphosphate DHAP, dihydroxyacetone phosphate G3P, glycerol 3-phosphate GAP, glyceraldehyde...

Reduction of phosphoglycerate by the combined action of phospho-glycerate kinase and triose phosphate ddiydrogenase results in the formation of triose phosphate (XII). This reduction is presumably effected... 

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