3oi7
Structure of the structure of the H13A mutant of Ykr043C in complex with sedoheptulose-1,7-bisphosphateStructure of the structure of the H13A mutant of Ykr043C in complex with sedoheptulose-1,7-bisphosphate
Structural highlights
FunctionSHB17_YEAST Sedoheptulose 1,7-bisphosphatase involved in riboneogenesis. Dephosphorylates sedoheptulose 1,7-bisphosphate (SBP), which is converted via the non-oxidative pentose phosphate pathway to ribose-5-phosphate. Has a fructose 1,6-bisphosphatase activity in vitro, but this is probably not biologically relevant, since deletion does not affect fructose 1,6-biphosphate (FBP) levels.[1] Publication Abstract from PubMedGlucose is catabolized in yeast via two fundamental routes, glycolysis and the oxidative pentose phosphate pathway, which produces NADPH and the essential nucleotide component ribose-5-phosphate. Here, we describe riboneogenesis, a thermodynamically driven pathway that converts glycolytic intermediates into ribose-5-phosphate without production of NADPH. Riboneogenesis begins with synthesis, by the combined action of transketolase and aldolase, of the seven-carbon bisphosphorylated sugar sedoheptulose-1,7-bisphosphate. In the pathway's committed step, sedoheptulose bisphosphate is hydrolyzed to sedoheptulose-7-phosphate by the enzyme sedoheptulose-1,7-bisphosphatase (SHB17), whose activity we identified based on metabolomic analysis of the corresponding knockout strain. The crystal structure of Shb17 in complex with sedoheptulose-1,7-bisphosphate reveals that the substrate binds in the closed furan form in the active site. Sedoheptulose-7-phosphate is ultimately converted by known enzymes of the nonoxidative pentose phosphate pathway to ribose-5-phosphate. Flux through SHB17 increases when ribose demand is high relative to demand for NADPH, including during ribosome biogenesis in metabolically synchronized yeast cells. Riboneogenesis in yeast.,Clasquin MF, Melamud E, Singer A, Gooding JR, Xu X, Dong A, Cui H, Campagna SR, Savchenko A, Yakunin AF, Rabinowitz JD, Caudy AA Cell. 2011 Jun 10;145(6):969-80. PMID:21663798[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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