O-Methylation of benzaldehyde derivatives by “lignin specific” caffeic acid 3-O-methyltransferase
نویسندگان
چکیده
منابع مشابه
Structural basis for the modulation of lignin monomer methylation by caffeic acid/5-hydroxyferulic acid 3/5-O-methyltransferase.
Caffeic acid/5-hydroxyferulic acid 3/5-O-methyltransferase (COMT) from alfalfa is an S-adenosyl-L-Met-dependent O-methyltransferase involved in lignin biosynthesis. COMT methylates caffeoyl- and 5-hydroxyferuloyl-containing acids, aldehydes, and alcohols in vitro while displaying a kinetic preference for the alcohols and aldehydes over the free acids. The 2.2-A crystal structure of COMT in comp...
متن کاملCharacterization of a caffeic acid 3-O-methyltransferase from wheat and its function in lignin biosynthesis.
Caffeic acid 3-O-methyltransferase (COMT) catalyzes the multi-step methylation reactions of hydroxylated monomeric lignin precursors, and is believed to occupy a pivotal position in the lignin biosynthetic pathway. A cDNA (TaCM) was identified from wheat and it was found to be expressed constitutively in stem, leaf and root tissues. The deduced amino acid sequence of TaCM showed a high degree o...
متن کاملStructural and compositional modifications in lignin of transgenic alfalfa down-regulated in caffeic acid 3-O-methyltransferase and caffeoyl coenzyme A 3-O-methyltransferase.
Isolated lignins from alfalfa deficient in caffeic acid 3-O-methyltransferase contained benzodioxanes resulting from the incorporation of the novel monomer, 5-hydroxyconiferyl alcohol. Due to the high level incorporated into the soluble lignin fraction and the use of sensitive NMR instrumentation, unique structural features were revealed. A new type of end-unit, the 5-hydroxyguaiacyl glycerol u...
متن کاملAcid detergent lignin, lodging resistance index, and expression of the caffeic acid O-methyltransferase gene in brown midrib-12 sudangrass
Understanding the relationship between acid detergent lignin (ADL) and lodging resistance index (LRI) is essential for breeding new varieties of brown midrib (bmr) sudangrass (Sorghum sudanense (Piper) Stapf.). In this study, bmr-12 near isogenic lines and their wild-types obtained by back cross breeding were used to compare relevant forage yield and quality traits, and to analyze expression of...
متن کاملDownregulation of caffeic acid 3-O-methyltransferase and caffeoyl CoA 3-O-methyltransferase in transgenic alfalfa. impacts on lignin structure and implications for the biosynthesis of G and S lignin.
Transgenic alfalfa plants were generated harboring caffeic acid 3-O-methyltransferase (COMT) and caffeoyl CoA 3-O-methyltransferase (CCOMT) cDNA sequences under control of the bean phenylalanine ammonia-lyase PAL2 promoter. Strong downregulation of COMT resulted in decreased lignin content, a reduction in total guaiacyl (G) lignin units, a near total loss of syringyl (S) units in monomeric and ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Phytochemistry
سال: 2004
ISSN: 0031-9422
DOI: 10.1016/j.phytochem.2004.01.017