Characterization of Acyltransferases in Plant Secondary Metabolism - PowerPoint PPT Presentation

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Characterization of Acyltransferases in Plant Secondary Metabolism
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Characterization of Acyltransferases in Plant Secondary Metabolism

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    1. Characterization of Acyltransferases in Plant Secondary Metabolism

    2. Secondary Metabolites Products that are not essential for normal growth and development of plants Natural products Multiple functions throughout the plants life cycle

    3. Functions and Applications of Secondary Metabolites

    4. Genetic Engineering of 2 Metabolic Pathway Aims to either increase or decrease the quantity of a certain compound 1. Change the expression of regulatory genes => regulation of multiple biosynthesis genes 2. Control the expression of one or a few structural genes => overcoming specific rate-limiting steps in the pathway

    5. Acyltransferases Acylation The process of adding an acyl group to a compound The structural and functional modification of compounds Acyltransferases A group of enzymes catalyzing the transfer of acyl groups A powerful means for engineering of secondary metabolites

    6. Versatile Acyltransferase (VAT) Family Protein family consisting of acyltransferases in secondary metabolism in plants and fungi Motif 1 (HXXXD):a general acid/base catalyst Motif 2:unknown function Motif 3 (DFGWG):catalytic activity

    7. Molecular Phylogenetic Tree of VAT

    8. Characterization of VATs Benzylalcohol acyltransferae (BEAT) Deacetylvindoline 4-O-acetyltransferase (DAT) Strawberry alcohol acyltransferase (SAAT) Anthocyanin acyltransferases (AAT)

    9. BEAT Benzylacetate A type of benzoid esters A major constituent of the floral scent of Clarkia breweri Important flavorants in ripe fruit and ingredients in perfumes Benzylalcohol acyltransferase (BEAT) Catalysis the formation of the ester bezylacetate

    10. Isolation of BEAT Genes

    11. Analysis of BEAT Activity

    12. Expression of BEAT

    13. DAT Vindoline Monoterpenoid indole alkaloids Use in cancer chemotherapy Low yields in the plant Deacetylvindoline 4-O-acetyltransferase (DAT) Catalysis of the last step in vindoline biosynthesis

    14. Isolation of DAT Gene

    15. Chemical Modification of DAT

    16. Light Induction of DAT Activity

    17. SAAT Volatile esters Production form all soft fruit species during ripening Flavor components of the majority of fruits Source of energy, vitamins, minerals and antioxidants Strawberry alcohol acyltransferase (SAAT) Catalysis of transacylation from acyl-CoA to an alcohol Key enzyme in aroma biochemistry Use of the last step in volatile esters biosynthesis

    18. Isolation of the SAAT Gene

    19. Analysis of SAAT Gene Expression

    20. Functional Expression of SAAT

    21. AAT in Salvia splendens Anthocyanin The largest subclass of plant flavonoid Attracting pollinators Protection of plants from various stresses Safety to human health Anthocyanin acyltransferases (AAT) Catalyze the acyl transfer from acyl-CoA to the sugar moiety of anthocyanin

    22. Isolation of AAT gene

    23. Analysis of Ss5MaT gene expression

    24. Applications of Acyltransferases Heterologous expressions Transformation SAAT gene of strawberry fruit into petunia leaves Metabolic engineering to modify flower color blue rose Modification of the functional and structural properties Only research for acyltransferase related to flavor and pigment ..

    25. Future Prospects

    26. References Acetyl-CoA:benzylalcohol acetyltransferase an enzyme involved in floral scent production in Clarkia breweri., Natalia Dudareva, John C. DAuria,Kyoung Hee Nam, Eran Pichersky, The Plant Journal, 1998, February, 297-304 The termial O-acetyltransferase involved in vindoline biosynthesis defines a new class of proteins responsible for coenzyme A-dependent acyl transfer., Venoit St-Pierre, Pierre Laflamme, Anne-Marie Alarco, Vincenzo De Luca, The plant Journal, 1998, March, 703-713 Identification of the SAAT gene involved in strawberry flavor biogenesis by use of DNA microarrays., Asaph Aharoni, Lepold C. P. Keizer, Harro J. Bouwmeester, Ann P. OConnell., The Plant Cell, 2000, May, 647-661 Engineering secondary metabolite production in plants., R. Verpoorte and J. Memelink, Current Opinion in Biotechnology, 2000, May, 181-187 Anthocyanin acyltransferases: specificities, mechanism, phylogenetics, and applications., Toru Nakayama, Hirokazu Suzuki, Tokuzo Nishino, Journal of Molecular Catalysis B: Enzymatic, 2003, March, 117132 Identification and characterization of a novel anthocyann malonyltransferase from scarlet sage (Salvia splendens) flowers., Hirokazu Suzuki, Shinya Sawade, Kazufumi Watanabe,Tokuzo Nishino, The Plant Journal, 2004, March, 994-1003