In the non-oxidative part of the pentose phosphate pathway, RPIA converts Ru5P to R5P which then is converted by ribulose-phosphate 3-epimerase to xylulose-5-phosphate (figure 3). (wikipedia.org)
1. Ashwell, G. and Hickman, J. Enzymatic formation of xylulose 5-phosphate from ribose 5-phosphate in spleen. (qmul.ac.uk)
3. Hurwitz, J. and Horecker, B.L. The purification of phosphoketopentoepimerase from Lactobacillus pentosus and the preparation of xylulose 5-phosphate. (qmul.ac.uk)
Ribose 5-phospha3
Ribose-5-phosphate isomerase (Rpi) encoded by the RPIA gene is an enzyme (EC 5.3.1.6) that catalyzes the conversion between ribose-5-phosphate (R5P) and ribulose-5-phosphate (Ru5P). (wikipedia.org)
The only known naturally occurring genetic mutation results in ribose-5-phosphate isomerase deficiency, discussed below. (wikipedia.org)
Mutations in this gene cause ribose 5-phosphate isomerase deficiency. (wikipedia.org)
Enzyme8
The systematic name of this enzyme class is D-ribose-5-phosphate aldose-ketose-isomerase. (wikipedia.org)
The enzyme is capable of bonding with the open-chain or ring form of the sugar-phosphate. (wikipedia.org)
The protein encoded by RPIA gene is an enzyme, which catalyzes the reversible conversion between ribose-5-phosphate and ribulose-5-phosphate in the pentose-phosphate pathway. (wikipedia.org)
A genetic aberration in glucose 6-phosphate dehydrogenase, a pivotal enzyme in the PPP, can disrupt this biochemical harmony, underscoring the pathway's indispensability in cellular metabolism and defense mechanisms. (microbiologynote.com)
the enzyme is called ribulose‐bisphosphate carboxylase/oxygenase (called Rubisco ). (cliffsnotes.com)
The 5‐carbon sugar phosphates are interconverted by the action of epimerase and isomerase to yield ribulose‐5‐phosphate, which is phosphorylated by the enzyme ribulose phosphate kinase to make RuBP, the acceptor of CO 2 . (cliffsnotes.com)
Ribulose phosphate kinase is active only when a cystine disulfide on the enzyme is reduced to two cysteines. (cliffsnotes.com)
The enzyme also converts D -erythrose 4-phosphate into D -erythrulose 4-phosphate and D -threose 4-phosphate. (qmul.ac.uk)
Glycolysis4
In scientific terms, the PPP is an essential metabolic pathway that functions concurrently with glycolysis , presenting itself as a quintessential player in maintaining cellular homeostasis through its diligent role in generating NADPH, pentoses, and ribose 5-phosphate. (microbiologynote.com)
In the present study, we considered the simulation of the main metabolic pathways such as glycolysis, TCA cycle, pentose phosphate (PP) pathway, and the anapleorotic pathways using enzymatic reaction models of E. coli . (biomedcentral.com)
The kinetic equations for the glycolysis and the pentose phosphate (PP) pathway have also been developed for E. coli to simulate the transient data obtained by the fast sampling system [ 8 ]. (biomedcentral.com)
Isomerase3
The glyceraldehyde‐3‐phosphate can be converted into the 6‐carbon sugar phosphate called fructose‐6‐phosphate by the reactions of triose phosphate isomerase, aldolase, and fructose bisphosphase. (cliffsnotes.com)
2. Dickens, F. and Williamson, D.H. Pentose phosphate isomerase and epimerase from animal tissues. (qmul.ac.uk)
An expression cassette containing 13 genes including Clostridium phytofermentans XylA , encoding D-xylose isomerase (XI), and enzymes of the pentose phosphate pathway was inserted in two copies in the genome of Ethanol Red. (biomedcentral.com)
Oxidative branch2
The oxidative branch of the pathway is a major source for NADPH which is needed for biosynthetic reactions and protection against reactive oxygen species. (wikipedia.org)
The pentose phosphate pathway (PPP) is divided into an oxidative branch that makes pentose phosphates and a non-oxidative branch that consumes pentose phosphates, though the non-oxidative branch is considered reversible. (mdpi.com)
Nucleic acid1
Dietary pentose sugars, a derivative of nucleic acid digestion, can be intertwined with the PPP, thereby revealing another layer of metabolic flexibility and adaptability provided by this pathway. (microbiologynote.com)
Triose1
The reaction sequence in the Calvin-Benson cycle is from triose phosphates to pentose phosphates, the opposite of the typical direction of the non-oxidative PPP. (mdpi.com)
Metabolic pathways5
Navigating through the biochemical intricacies of the PPP provides a splendid panorama of how cells masterfully exploit metabolic pathways, in a manner that is attuned to their physiological, biosynthetic, and defensive needs, thereby maintaining a harmonious cellular and systemic physiological state. (microbiologynote.com)
In essence, the PPP is a testament to nature's biochemical prowess, revealing how metabolic pathways, through eons of evolutionary fine-tuning, have been sculpted into multifaceted biochemical networks, proficiently catering to the myriad metabolic and defensive demands of the cell. (microbiologynote.com)
Although several models have so far been proposed, most of them focus on the specific metabolic pathways. (biomedcentral.com)
It is preferred to model the whole of the main metabolic pathways in Escherichia coli , allowing for the estimation of energy generation and cell synthesis, based on intracellular fluxes and that may be used to characterize phenotypic growth. (biomedcentral.com)
It was shown to be useful to simulate the main metabolism of E. coli for understanding metabolic changes inside the cell in response to specific pathway gene knockouts, considering the whole main metabolic pathways. (biomedcentral.com)
Enzymatic1
The first step in the catalysis is the docking of the pentose into the active site in the enzymatic cleft, followed by allosteric closing of the cleft. (wikipedia.org)
Intermediates2
The end result of the reaction essentially is the conversion of the pentose phosphates to intermediates used in the glycolytic pathway. (wikipedia.org)
Concurrently, the PPP can transmute the carbon skeletons of dietary carbohydrates into intermediates apt for glycolytic and gluconeogenic pathways, thereby enabling the cell to adeptly navigate through the metabolic intricacies and adapt to varying physiological contexts. (microbiologynote.com)
Sugars2
The PPP showcases its role by executing two meticulously orchestrated phases: the oxidative phase, where glucose 6-phosphate is oxidized to produce NADPH and ribulose 5-phosphate, and the non-oxidative phase, which is engaged in the synthesis of 5-carbon sugars, contributing significantly to the synthesis of nucleotides and nucleic acids. (microbiologynote.com)
Unfortunately, baker's yeast is unable to efficiently metabolize pentose sugars, particularly D-xylose, which accounts for up to 35% of total sugars in xylan-rich lignocellulosic biomass such as hard woods and straw [ 3 ]. (biomedcentral.com)
Reactions3
The Pentose Phosphate Pathway (PPP) primarily resides within the cytosol of cells, which is the aqueous component of the cytoplasm, a matrix in which various cellular organelles are suspended and numerous metabolic reactions transpire. (microbiologynote.com)
Regeneration of ribulose bisphosphate occurs by the same reactions that occur in the hexose‐monophosphate shunt. (cliffsnotes.com)
Glucose3
During the first phase of PPP, G6P is converted to 6-phosphogluconolactone by glucose 6-phosphate dehydrogenase which results in the production of NADPH. (breastcancertalk.net)
Embarking on an exploration into cellular metabolism, the Pentose Phosphate Pathway (PPP) commands particular attention, not merely for its role in glucose metabolism but also for its crucial involvement in cellular biosynthesis and antioxidant defenses. (microbiologynote.com)
The rest of the Calvin cycle is involved in interconversion of carbohydrates to make glucose (or starch) and the regeneration of the ribulose‐bisphosphate acceptor. (cliffsnotes.com)
Converts1
In the oxidative part of the pentose phosphate pathway, RpiA converts Ru5P to the final product, R5P through the isomerization reaction (figure 3). (wikipedia.org)
RuBP1
RPIA is essential in the cycle, as Ru5P generated from R5P is subsequently converted to ribulose-1,5-bisphosphate (RuBP), the acceptor of carbon dioxide in the first dark reaction of photosynthesis (Figure 3). (wikipedia.org)
Carbon2
The CcpA regulon comprises genes involved in sugar uptake, fermentation and amino acids metabolism, confirming the role of CcpA as a link between carbon and nitrogen pathways. (studyres.com)
Conversely, in tissues where the biosynthetic activities, particularly those related to fatty acid and sterol synthesis, are in full swing, the NADPH produced by the PPP is channeled to support these reductive biosynthetic pathways. (microbiologynote.com)
Inhibitor2
This cleft is capable of closing upon recognition of the phosphate on the pentose (or an appropriate phosphate inhibitor). (wikipedia.org)
The inherently higher robustness and tolerance of S. cerevisiae to various inhibitors gives it a head start in programs aimed at developing strains with extreme inhibitor tolerance, able to efficiently ferment hexoses and pentoses in concentrated lignocellulose hydrolysates [ 6 ]. (biomedcentral.com)
KEGG1
The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis indicated that low JA concentration (especially 5 μM) exhibited the promotion effects on tuber development in various cellular processes. (biomedcentral.com)
RpiA plays an essential role in the metabolism of plants and animals, as it is involved in the Calvin cycle which takes place in plants, and the pentose phosphate pathway which takes place in plants as well as animals. (wikipedia.org)
Moreover, the effects of the knockout of such pathways as Ppc, Pck and Pyk on the metabolism were simulated. (biomedcentral.com)
Acid1
Notably, NADPH generated through the oxidative phase is pivotal for counteracting oxidative stress and facilitating reductive biosynthesis, such as fatty acid synthesis. (microbiologynote.com)
Calvin2
please see http://www3.interscience.wiley.com/cgi-bin/fulltext/97516673/PDFSTAR) Due to its role in the pentose phosphate pathway and the Calvin cycle, RpiA is highly conserved in most organisms, such as bacteria, plants, and animals. (wikipedia.org)
This pathway is sometimes called the Calvin‐Benson cycle, after the biochemists who elucidated it. (cliffsnotes.com)
Cells2
A meticulous exploration of its function in these cells unravels its imperative role in generating a substantial amount of NADPH, which is instrumental in maintaining the reduced form of glutathione. (microbiologynote.com)
Furthermore, cells like erythrocytes, which are persistently exposed to oxidative stress, exploit the PPP to generate NADPH, maintaining a cellular environment that is conducive to combating oxidative damage. (microbiologynote.com)
Production2
Once intracellular fluxes were computed by this model, the specific ATP production rate, the specific CO 2 production rate, and the specific NADPH production rate could be estimated. (biomedcentral.com)
The CO 2 production rate could be used to estimate cell yield, and the specific NADPH production rate could be used to determine the flux of the oxidative PP pathway. (biomedcentral.com)