EC Number   |
General Information |
Reference |
|---|
    1.1.1.282 | evolution |
Escherichia coli constitutively expresses two shikimate dehydrogenase paralogues, AroE and the NAD+-dependent enzyme quinate/shikimate dehydrogenase (YdiB), sharing 25% sequence identity. While AroE is NADP+-dependent, YdiB uses NADP+ or NAD+. Contrary to AroE, YdiB displays a clear activity on quinate, with either NADP+ or NAD+ as a cofactor in addition to shikimate |
-, 761708 |
| 1.1.1.282 | evolution |
members of the same gene family encode enzymes with either shikimate or quinate dehydrogenase activity. Plant SDHs are generally more similar to bacterial SDH/QDH YdiB (25-30% similarity) than to bacterial SDH AroE (21-28%) |
740724 |
| 1.1.1.282 | evolution |
plant QDHs arose directly from bifunctional dehydroquinate dehydratase-shikimate dehydrogenases (DHQD-SDHs) through different convergent evolutionary events, detailed phylogenetic analysis, overview. Eudicot and conifer QDHs arose early in vascular plant evolution whereas Brassicaceae QDHs emerged late, process of recurrent evolution of QDH. This family of proteins independently evolved NAD+ and NADP+ specificity in eudicots. The acquisition of QDH activity by these proteins is accompanied by the inactivation or functional evolution of the DHQD domain, as verified by enzyme activity assays and as reflected in the loss of key DHQD active site residues |
762145 |
| 1.1.1.282 | evolution |
SDH is the archetypal member of a large protein family, which contains at least four additional functional classes with diverse metabolic roles. The different members of the SDH family share a highly similar three-dimensional structure and utilize a conserved catalytic mechanism, but exhibit distinct substrate preferences |
-, 739956 |
| 1.1.1.282 | evolution |
the enzyme belongs to the QDH family, phylogenetic reconstruction of the SDH/QDH gene family across land plants, overview. SDH and QDH belong to the same gene family, which diverged into two phylogenetic clades after a defining gene duplication just prior to the angiosperm/gymnosperm split. Non-seed plants that diverged before this duplication harbour only a single gene of this family. Extant representatives from the chlorophytes (Chlamydomonas reinhardtii), bryophytes (Physcomitrella patens) and lycophytes (Selaginella moellendorfii) encoded almost exclusively SDH activity in vitro. A reconstructed ancestral sequence representing the node just prior to the gene duplication also encoded SDH activity. Quinate dehydrogenase activity was gained only in seed plants following gene duplication. Quinate dehydrogenases of gymnosperms, e.g. Pinus taeda, may be reminiscent of an evolutionary intermediate since they encode equal SDH and QDH activities. The second copy in Pinus taeda maintains specificity for shikimate similar to the activity found in the angiosperm SDH sister clade. The codon for a tyrosine residue within the active site displays a signature of positive selection at the node defining the QDH clade, where it changed to a glycine. Replacing the tyrosine with a glycine in a highly shikimate-specific angiosperm SDH is sufficient to gain some QDH function. Thus, very few mutations are necessary to facilitate the evolution of QDH genes. The two proteins from Pinus taeda are chosen to represent the post-duplication SDH and QDH clades from gymnosperms. The single-copy genes from Selaginella moellendorffii, Physcomitrella patens and Chlamydomonas reinhardtii are selected to represent the pre-duplication lycopod, bryophyte and green algal clades, respectively. Thr381 is conserved in most members across all SDH clades but was replaced under positive selection by Gly in the branch leading into the seed plant QDH clade |
762146 |
| 1.1.1.282 | malfunction |
disruption of the qdh gene in prevents growth on both compounds, demonstrating the important role of the enzyme in hydroaromatic catabolism |
-, 739956 |
| 1.1.1.282 | malfunction |
in the ydiB knockout mutant, QA production is 6.17% relative to SA (mol/mol), indicating that the inactivation of ydiB is a suitable strategy to reduce QA production below 10% (mol/mol) relative to SA in culture fermentations for SA production. The inactivation of ydiB in Escherichia coli strain PB12.SA22 and the reduction in QA production support the role of YdiB in the synthesis of this compound from DHQ. In the absence of YdiB, the DHS concentration detected in supernatant cultures is maintained relatively constant during the stationary phase |
-, 761708 |
| 1.1.1.282 | metabolism |
link between reactions catalysed by the shikimate pathway enzyme dehydroquinate dehydratase (DQD)/shikimate dehydrogenase (SDH) and quinate dehydrogenase (QDH) involved in quinate metabolism. Shikimate is produced from dehydroquinate via a two-step reaction and subsequently channelled to downstream reactions in the pathway. Quinate is reversibly formed from a side branch of the shikimate pathway from dehydroquinate and may be converted to more structurally complex secondary metabolites or to dehydroquinate to fuel the shikimate pathway |
762146 |
| 1.1.1.282 | metabolism |
reactions comprising the shikimate/quinate cycle, overview |
740724 |
| 1.1.1.282 | metabolism |
the enzyme catalyzes the fourth step of the shikimate pathway, a conserved biosynthetic route in plants, fungi, bacteria, and apicomplexan parasites |
-, 739956 |
