EC Number   |
General Information |
Reference |
|---|
  2.5.1.45 | evolution |
the gene encoding enzyme HSS origins from a single duplication event of a single-copy gene encoding deoxyhypusine synthase, DHS, EC 2.5.1.46. This duplication event was followed by several losses of a functional gene copy attributable to gene loss or pseudogenization. Statistical analyses of sequence data suggest that, in those lineages in which the gene copy was successfully recruited as HSS, the gene duplication event was followed by phases of various selection pressures, including purifying selection, relaxed functional constraints, and possibly positive Darwinian selection |
739292 |
| 2.5.1.45 | malfunction |
transgenic tobacco plants are generated expressing Senecio vernalis homospermidine synthase. Analyses of the polyamine content reveals that, in the transgenic plants, about 80% of spermidine is replaced by homospermidine without any conspicuous modifications of the phenotype. Tracer-feeding experiments and gas chromatographic analyses suggest that these high levels of homospermidine are not sufficient to explain the formation of alkaloid precursors |
706254 |
| 2.5.1.45 | metabolism |
homospermidine synthase is the first pathway-specific enzyme of pyrrolizidine alkaloid biosynthesis |
739292 |
| 2.5.1.45 | metabolism |
polymanines in Crotalaria are detectable only when the plants form nodules after infection with their rhizobial partner. But polyamines are synthesized by the plant not by the mcirosymbiont |
739550 |
| 2.5.1.45 | metabolism |
the enzyme is first specific enzyme in the biosynthesis of pyrrolizidine alkaloids |
739261 |
| 2.5.1.45 | metabolism |
the enzyme is first specific enzyme in the biosynthesis of pyrrolizidine alkaloids, it is involved in the biosynthetic pathway of the lycopsamine-type polyamine indicine N-oxide |
739261 |
| 2.5.1.45 | more |
exogenously applied nitrate has no impact on polyamine biosynthesis, and enzyme activity, but nodulation is inhibited at higher levels of nitrate by autoregulation |
739550 |
| 2.5.1.45 | more |
the Convulvulaceae species Ipomoea alba contains ipanguline-type polyamines. Detection of sites that are involved in optimizing HSS functionality |
739292 |
| 2.5.1.45 | more |
the Convulvulaceae species Ipomoea hederifolia contains ipanguline-type polyamines. Detection of sites that are involved in optimizing HSS functionality |
739292 |
| 2.5.1.45 | more |
the Convulvulaceae species Ipomoea meyeri contains ipanguline- and triangularine-type polyamines. Detection of sites that are involved in optimizing HSS functionality |
739292 |
