A tetrose is a monosaccharide with 4 carbon atoms. They have either an aldehyde functional group in position 1 (aldotetroses) or a ketone functional group in position 2 (ketotetroses).
Transketolase is an enzyme that, in humans, is encoded by the TKT gene. It participates in both the pentose phosphate pathway in all organisms and the Calvin cycle of photosynthesis. Transketolase catalyzes two important reactions, which operate in opposite directions in these two pathways. In the first reaction of the non-oxidative pentose phosphate pathway, the cofactor thiamine diphosphate accepts a 2-carbon fragment from a 5-carbon ketose (D-xylulose-5-P), then transfers this fragment to a 5-carbon aldose (D-ribose-5-P) to form a 7-carbon ketose (sedoheptulose-7-P). The abstraction of two carbons from D-xylulose-5-P yields the 3-carbon aldose glyceraldehyde-3-P. In the Calvin cycle, transketolase catalyzes the reverse reaction, the conversion of sedoheptulose-7-P and glyceraldehyde-3-P to pentoses, the aldose D-ribose-5-P and the ketose D-xylulose-5-P.
Transaldolase is an enzyme of the non-oxidative phase of the pentose phosphate pathway. In humans, transaldolase is encoded by the TALDO1 gene.
Ribose 5-phosphate (R5P) is both a product and an intermediate of the pentose phosphate pathway. The last step of the oxidative reactions in the pentose phosphate pathway is the production of ribulose 5-phosphate. Depending on the body's state, ribulose 5-phosphate can reversibly isomerize to ribose 5-phosphate. Ribulose 5-phosphate can alternatively undergo a series of isomerizations as well as transaldolations and transketolations that result in the production of other pentose phosphates as well as fructose 6-phosphate and glyceraldehyde 3-phosphate.
Sedoheptulose 7-phosphate is an intermediate in the pentose phosphate pathway.
Ribose-phosphate diphosphokinase is an enzyme that converts ribose 5-phosphate into phosphoribosyl pyrophosphate (PRPP). It is classified under EC 2.7.6.1.
In enzymology, a phosphopentomutase is an enzyme that catalyzes the chemical reaction
In enzymology, a S-methyl-5-thioribose-1-phosphate isomerase is an enzyme that catalyzes the chemical reaction
The enzyme deoxyribose-phosphate aldolase catalyzes the reversible chemical reaction
In enzymology, a 1-deoxy-d-xylulose-5-phosphate synthase (EC 2.2.1.7) is an enzyme in the non-mevalonate pathway that catalyzes the chemical reaction
In enzymology, a fluorothreonine transaldolase is an enzyme that catalyzes the chemical reaction
In enzymology, a formaldehyde transketolase is an enzyme that catalyzes the chemical reaction
In enzymology, a 3-deoxy-8-phosphooctulonate synthase (EC 2.5.1.55) is an enzyme that catalyzes the chemical reaction
In enzymology, a pyridoxine 5'-phosphate synthase (EC 2.6.99.2) is an enzyme that catalyzes the chemical reaction
In enzymology, a deoxyuridine phosphorylase is an enzyme that catalyzes the chemical reaction
In enzymology, a S-methyl-5'-thioadenosine phosphorylase is an enzyme that catalyzes the chemical reaction
Thymidine phosphorylase is an enzyme that is encoded by the TYMP gene and catalyzes the reaction:
In enzymology, a ribose-5-phosphate adenylyltransferase is an enzyme that catalyzes the chemical reaction
Transaldolase deficiency is a disease characterised by abnormally low levels of the transaldolase enzyme. It is a metabolic enzyme involved in the pentose phosphate pathway. It is caused by mutation in the transaldolase gene (TALDO1). It was first described by Verhoeven et al. in 2001.
3-Deoxy-D-arabinoheptulosonate 7-phosphate (DAHP) synthase is the first enzyme in a series of metabolic reactions known as the shikimate pathway, which is responsible for the biosynthesis of the amino acids phenylalanine, tyrosine, and tryptophan. Since it is the first enzyme in the shikimate pathway, it controls the amount of carbon entering the pathway. Enzyme inhibition is the primary method of regulating the amount of carbon entering the pathway. Forms of this enzyme differ between organisms, but can be considered DAHP synthase based upon the reaction that is catalyzed by this enzyme.
