EC Number   |
General Information |
Reference |
|---|
  1.3.99.28 | evolution |
homologous complementation of CrtI from Pantoea agglomerans with the Pantoea agglomerans carotenogenic module expressing CrtEPAG -CrtBPAG |
-, 724038 |
| 1.3.99.28 | evolution |
homologous complementation of CrtI from Pantoea agglomerans with the Pantoea agglomerans carotenogenic module expressing CrtEPAG-CrtBPAG |
-, 724038 |
| 1.3.99.28 | evolution |
the enzyme belongs to the CrtI family of enzymes, analysis of the phylogenetic tree of a subset of phytoene desaturases from the CrtI family, overview. Recombinant expression of eight codon optimized CrtI enzymes from different clades in a bacterial system reveals that three CrtI enzymes can catalyse up to six desaturations, forming tetradehydrolycopene. Existence of characteristic patterns of desaturated molecules associated with various CrtI clades. Variations in the reaction rates and binding constants can explain the various carotene patterns observed. Relationship between genetic and functional evolution of certain CrtI enzymes, overview |
-, 759253 |
| 1.3.99.28 | metabolism |
carotenoid biosynthesis starts with the symmetrical condensation of two geranylgeranyl diphosphate molecules, forming phytoene. A series of successive desaturation reactions convert phytoene into phytofluene, zeta-carotene, neurosporene, lycopene. These desaturation reactions can be accomplished by a single enzyme (poly-trans pathway) or through a cascade of different enzymes (poly-cis pathway). In algae and plants, four different enzymes are necessary to form the final product (all-trans-lycopene). The phytoene and the zeta-carotene desaturases (PDS and ZDS, respectively) add double bonds in the cis-conformation. ZISO (zeta-carotene isomerase) and CRTISO (prolycopene isomerase) convert the cis-carotenes into di-cis-zeta-carotene and all-trans-lycopene, respectively. By contrast to other phytoene desaturases, CrtI are versatile enzymes classified into four enzymatic subgroups (EC 1.3.99.28, EC 1.3.99.29, EC 1.3.99.30, and EC 1.3.99.31) based on the last product they presumably produce (from zeta-carotene to didehydrolycopene). Carotene diversity can be further expanded in later steps with the addition of one or two rings by lycopene cyclases, thereby producing an extensive variety of symmetrical or asymmetrical cyclised carotenes, such as beta-zeacarotene, dehydro-beta-carotene, gamma-carotene, beta-carotene, and the fungi-specific torulene. When expressed in heterologous hosts, CrtI enzymes exhibit distinct desaturation patterns, CrtI enzyme activities may depend on the experimental conditions and thus be inconsistent with the patterns generated in the natural host. Rhodobacter capsulatus strain SB1003 also produces lycopene in vitro (cf. EC 1.3.99.31) |
-, 759253 |
| 1.3.99.28 | metabolism |
the enzyme is a pathway branch point enzyme in the carotenoid pathway |
-, 724038 |
| 1.3.99.28 | metabolism |
the enzyme is a pathway branch point enzyme in the carotenoid pathway. Carotenoid pathways of Pantoea agglomerans wild-type and reconstructed pathways in Escherichia coli, overview |
-, 724038 |
| 1.3.99.28 | more |
comparison of the natural evolution and kinetic properties of selected CrtI enzymes expressed and assayed under standardised conditions. Potentially all CrtI enzymes can catalyse desaturation reactions that progress beyond the already observed end-products and the pattern of products formed originates from variations in the reaction rates rather than affinity constants |
-, 759253 |
| 1.3.99.28 | more |
Leu208 is exchanged in the neurosporene or lycopene-forming desaturase |
-, 711020 |
| 1.3.99.28 | more |
Rhodobacter azotoformans cntains a carotenogenesis gene cluster with an unusual organization and a phytoene desaturase catalyzing both three- and four-step desaturations. CrtI from Rhodobacter azotoformans CGMCC 6086 can produce three-step desaturated neurosporene and four-step desaturated lycopene as major products, see also EC 1.3.99.31, together with small amounts of five-step desaturated 3,4-didehydrolycopene, EC 1.3.99.30 |
-, 725042 |
| 1.3.99.28 | physiological function |
involved in carotenoid biosynthesis |
712316, 712333, 712351 |
