Download MendeleyRiboneogenesis in yeast.
Clasquin, M.F., Melamud, E., Singer, A., Gooding, J.R., Xu, X., Dong, A., Cui, H., Campagna, S.R., Savchenko, A., Yakunin, A.F., Rabinowitz, J.D., Caudy, A.A.(2011) Cell 145: 969-980
- PubMed: 21663798
- DOI: https://doi.org/10.1016/j.cell.2011.05.022
- Primary Citation of Related Structures:
3OI7 - PubMed Abstract:
Glucose 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.
Organizational Affiliation:
Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton NJ 08544, USA.
