LIS - Legume Information System
Information about legume traits for crop improvement
CicerMine
v5.1.0.3
Cicer data from the Legume Information System
v5.1.0.3
Cicer data from the Legume Information System
| Type | Domain |
| Description | Transketolase (TK) catalyses the reversible transfer of a two-carbon ketol unit from xylulose 5-phosphate to an aldose receptor, such asribose 5-phosphate, to form sedoheptulose 7-phosphate and glyceraldehyde 3- phosphate. This enzyme, together with transaldolase, provides a link betweenthe glycolytic and pentose-phosphate pathways. TK requires thiamine pyrophosphate as a cofactor. In most sources where TK hasbeen purified, it is a homodimer of approximately 70 Kd subunits. TK sequences from a variety of eukaryotic and prokaryotic sources [, ] show that theenzyme has been evolutionarily conserved. In the peroxisomes of methylotrophic yeast Pichia angusta (Yeast) (Hansenula polymorpha), there is ahighly related enzyme, dihydroxy-acetone synthase (DHAS) (also known as formaldehyde transketolase), which exhibits a very unusualspecificity by including formaldehyde amongst its substrates. 1-deoxyxylulose-5-phosphate synthase (DXP synthase) [] is an enzyme so farfound in bacteria (gene dxs) and plants (gene CLA1) which catalyses the thiamine pyrophosphoate-dependent acyloin condensation reaction between carbonatoms 2 and 3 of pyruvate and glyceraldehyde 3-phosphate to yield 1-deoxy-D-xylulose-5-phosphate (dxp), a precursor in the biosynthetic pathway to isoprenoids, thiamine (vitamin B1), and pyridoxol (vitamin B6). DXP synthaseis evolutionary related to TK. The N-terminal section, contains a histidine residue which appears to function inproton transfer during catalysis [ ]. This entry represents the centralsection there are conserved acidic residues that are part of the active cleft and may participate in substrate-binding [].This group of proteins includes transketolase enzymes and 2-oxoisovalerate dehydrogenasebeta subunit . Both these enzymes utilise thiamine pyrophosphate as a cofactor, suggestingthere may be common aspects in their mechanism of catalysis. |
| Short Name | Transketolase-like_Pyr-bd |
