Sandbox Reserved 660: Difference between revisions

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4-Coumarate-coenzyme A ligase (4CL) is an enzyme that functions early in the general  phenylpropanoid pathway by producing the monolignol precursor p-coumaroyl-CoA. 4CL silencing in angiosperm species such as tobacco, Arabidopsis and Populus tremuloides causes lignin reductions in the range of 25% to 45%. However, the impacts of these manipulations on lignin composition varied. 4CL silencing in tobacco preferentially depleted syringyl (S) lignin units, which are prominent in wood fibers. 4CL silencing in Arabidopsis depleted only guaiacyl (G) lignin units, which are enriched in vessel elements, whereas silencing of 4CL in P.tremuloides had no impact on the S-G ratio. An increase in the S-G ratio in P.tremuloides was only recorded when 4CL silencing was combined with the over expression of coniferaldehyde 5-hydroxylase. These differences in lignin composition could be the consequence of silencing 4CL isoforms with different substrate preferences, or they could reflect the in adequacies or limitations of analytical procedures used for lignin analysis[5].
4-Coumarate-coenzyme A ligase (4CL) is an enzyme that functions early in the general  phenylpropanoid pathway by producing the monolignol precursor p-coumaroyl-CoA. 4CL silencing in angiosperm species such as tobacco, Arabidopsis and Populus tremuloides causes lignin reductions in the range of 25% to 45%. However, the impacts of these manipulations on lignin composition varied. 4CL silencing in tobacco preferentially depleted syringyl (S) lignin units, which are prominent in wood fibers. 4CL silencing in Arabidopsis depleted only guaiacyl (G) lignin units, which are enriched in vessel elements, whereas silencing of 4CL in P.tremuloides had no impact on the S-G ratio. An increase in the S-G ratio in P.tremuloides was only recorded when 4CL silencing was combined with the over expression of coniferaldehyde 5-hydroxylase. These differences in lignin composition could be the consequence of silencing 4CL isoforms with different substrate preferences, or they could reflect the in adequacies or limitations of analytical procedures used for lignin analysis[5].


==References==


1. Ralph, J., Brunow, G., Harris, P. J., Dixon, R. A., Schatz, P. F., and Boerjan, W. 2008. Lignification: Are  lignins biosynthesized via simple combinatorial chemistry or via proteinaceous control and template replication? In F. Daayf, A. El Hadrami, L. Adam and G. M. and Ballance (eds.), Recent Advances in Polyphenol Research. Wiley-Blackwell Publishing, Oxford, UK.
1. Ralph, J., Brunow, G., Harris, P. J., Dixon, R. A., Schatz, P. F., and Boerjan, W. 2008. Lignification: Are  lignins biosynthesized via simple combinatorial chemistry or via proteinaceous control and template replication? In F. Daayf, A. El Hadrami, L. Adam and G. M. and Ballance (eds.), Recent Advances in Polyphenol Research. Wiley-Blackwell Publishing, Oxford, UK.


2. Ralph, J., Lundquist, K., Brunow, G., Lu, F., Kim, H., Schatz, P.F., Marita, J.M., Hatfield, R., Ralph, S.A., Christensen, J.H., and Boerjan, W. 2004. Lignins: Natural polymers from oxidative coupling of 4-hydroxyphenylpropanoids. Phytochem. Rev. 3:29-60.
2. Ralph, J., Lundquist, K., Brunow, G., Lu, F., Kim, H., Schatz, P.F., Marita, J.M., Hatfield, R., Ralph, S.A., Christensen, J.H., and Boerjan, W. 2004. Lignins: Natural polymers from oxidative coupling of 4-hydroxyphenylpropanoids. Phytochem. Rev. 3:29-60. <http://www.fpl.fs.fed.us/documnts/pdf2004/fpl_2004_ralph001.pdf >


3. HU, Y.; GAI, Y.; YIN, L.; WANG, X.; FENG, C.; FENG, L.; LI, D.; JIANG, X.N. and WANG, D.C. (2010). Crystal structures  of a Populus  tomentosa 4-coumarate:CoA ligase shed light on its enzymatic mechanisms.  The Plant Cell, vol. 22, no. 9, p. 3093-3104
3. HU, Y.; GAI, Y.; YIN, L.; WANG, X.; FENG, C.; FENG, L.; LI, D.; JIANG, X.N. and WANG, D.C. (2010). Crystal structures  of a Populus  tomentosa 4-coumarate:CoA ligase shed light on its enzymatic mechanisms.  The Plant Cell, vol. 22, no. 9, p. 3093-3104 < http://www.ncbi.nlm.nih.gov/pubmed/20841425 >


4. Gulick, A.M. (2009). Conformational dynamics in the Acyl-CoA synthetases, adenylation  domains of  non-ribosomal peptide synthetases, and firefly luciferase. ACS Chem. Biol. 4: 811–827
4. Gulick, A.M. (2009). Conformational dynamics in the Acyl-CoA synthetases, adenylation  domains of  non-ribosomal peptide synthetases, and firefly luciferase. ACS Chem. Biol. 4: 811–827                                     < http://pubs.acs.org/doi/abs/10.1021/cb900156h >


5. Wagner, A., Donaldson, L., Kim, H., Flint, H., Phillips, L., Steward, D., Torr, K., Koch, G., Schmitt, U., & Ralph, J. (2009). Suppression of 4-coumarate-CoA ligase in the coniferous gymnosperm Pinus radiata. Plant Physiology, 149, 370-383.
5. Wagner, A., Donaldson, L., Kim, H., Flint, H., Phillips, L., Steward, D., Torr, K., Koch, G., Schmitt, U., & Ralph, J. (2009). Suppression of 4-coumarate-CoA ligase in the coniferous gymnosperm Pinus radiata. Plant Physiology, 149, 370-383. <http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2613735/>


6. http://www.rcsb.org/pdb/explore/explore.do?structureId=3a9v
6. http://www.rcsb.org/pdb/explore/explore.do?structureId=3a9v
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