EC Number   |
General Information |
Reference |
|---|
    5.4.99.39 | evolution |
analysis of conserved domains and the evolutionary relationships between different beta-amyrin synthases from plants, sequence comparisons and phylogenetic analysis, detailed overview. The enzyme belongs to the family of oxidosqualene cyclases (OSC) |
748823 |
| 5.4.99.39 | evolution |
PlgOSC1 not only contains a DCTAE motif that is implicated in substrate binding, but also has four repeats of the QXXXGXW motif, which is a typical feature of the triterpene synthase superfamily. PlgOSC1 has a Try residue in the MWCYCR motif that plays a role in the formation of beta-amyrin |
747921 |
| 5.4.99.39 | evolution |
residue F474 of Euphorbia tirucalli beta-amyrin cyclase is highly conserved in the superfamily of oxidosqualene cyclases |
748805 |
| 5.4.99.39 | evolution |
the enzyme is a member of the oxidosqualene cyclase (OSC) family |
749323 |
| 5.4.99.39 | evolution |
the sequence of the mature protein contains the highly conserved motifs (QXXXGXW/DCTAE) of OSCs and (MWCYCR) of beta-amyrin synthases |
747786 |
| 5.4.99.39 | malfunction |
enzyme mutant F474A and F474G produces significantly larger amounts of the bicyclic products and a decreased amount of beta-amyrin compared to wild-type. The mutant variant F474A produces (9betaH)-polypoda-7,13,17,21-tetraen-3beta-ol and (9betaH)-polypoda-8(26),13,17,21-tetraen-3beta-ol, which are generated from a chair-boat folding conformation. Substitutions with aliphatic amino acids lacking Pi-electrons such as Val, Leu, and Met lead to a significantly decreased production of bicyclic compounds, and in turn exhibit a higher production of beta-amyrin |
748805 |
| 5.4.99.39 | malfunction |
RNAi-directed suppression of GsAS1 in Gentiana straminea decreases oleonolic acid levels by 65.9% |
749323 |
| 5.4.99.39 | malfunction |
RNAi-directed suppression of GsAS2 in Gentiana straminea decreasing oleonolic acid levels by 21.0% |
749323 |
| 5.4.99.39 | malfunction |
saponin biosynthesis in soybean seeds is suppressed through RNA interference-mediated beta-amyrin synthase gene silencing |
716502 |
| 5.4.99.39 | malfunction |
the Gly and Ala variants with a smaller bulk size at position 483, compared to wild-type Val483, predominantly afford monocyclic camelliol C, which suggests that the orientation of the (3S)-2,3-oxidosqualene substrate is not appropriately arranged in the reaction cavity as a result of the decreased bulk size, leading to failure of its normal folding into the chair-chair-chair-boat-boat conformation. The Ile variant, with a somewhat larger bulk, affords beta-amyrin as the dominant product. Various point mutants of Trp534 exhibit significantly decreased enzymatic activities and provide no aberrantly cyclized products, although the aromatic Phe and Tyr residues are incorporated and the steric sizes of the aliphatic residues are altered. Therefore, the Trp534 residue does not stabilize the transient cation through a cation-Pi interaction. Altering the steric bulk at the Met729 position afforded the pentacyclic skeletons |
747546 |
