Plant Omethyltransferases

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Plant O-methyltransferases

• Sara Blumer
• FW 5510
• 04.17-01

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Plant O-methyltransferases

• Three classes of OMT
• OMT I
• caffeate pathway (lignin biosynthesis)
• COMT
• CCoAOMT
• OMT II
• flavanoid pathways
• OMT III
• acceptor molecules
• myo-inositol

Ibrahim RK et al., 1998 Plant Molecular Biology
361-10
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Caffeate OMT and Caffeoyl CoA OMT
http//forestry.mtu.edu/woodscience/pbrc/personnel
/cpjoshi/lignin/
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Plant O-methyltransferases

• According to BRENDA DB
• COMT first isolated in 1975
• Spinach
• Poulton, J.E., Butt, V.S. 1975

http//www. srs.ebi.ac.uk/
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(No Transcript)
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OMT I PAUPDisplay
No Bootstrapping
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Caffeate OMT
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Caffeoyl CoA OMT
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OMT II PAUPDisplay
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OMT Consensus Sequence

• Used pileup and pretty to find consensus
• Ibrahim et al. 1998
• Found 5 consensus sites in the middle of the
  protein
• I LVDVGGGxG
• II GINFDLPHV
• III EHVGGDMF
• IV KGKVI
• V GGKERT

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COMT Consensus
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CCoAOMT Consensus
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OMT II Consensus
----------------M--MGST-NNHNNLTP-EEEEEEACLFAMQLA
SASVLP MVLKAA IELDVLEIIA KAGG-GAYVSPSEIASQLS
TL--N-QAPTML DRMLRLLASYSVLTCNLRTLED-DGGVER
LYGLAPVCKFLVKNEDL--GVSMAPLVLMNQDKVLMESWY
HLKDAVLDGGIPLFNKAYGMTHA-TFFEYHGTDPRFNKVFN
RGMADHSTITMKKILELYKGVFEGLKSLVDVGGGTGAT-NMI
VSKYPTIKGINFDLPHVIEDAPAYPGVEHVGGDMFVSVPKG
DAIFMKWILHDWSDEHCLKFLKNCYEALPANEK-GKVIIVE-ILPV-PDT
-LA-K-CQLDNIMLAH NPGGKERTEKEFEAL-KKA
GFTGFKILV-CGAFGSWEVM EFCK-I-N-
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OMT III Consensus
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Populus tremuloides COMT I Promoter

• Unique promoter in lignin biosynthesis
• lacks common phenylpropanoid elements
• Analysis using PLACE and CARE
• Light regulated elements
• GATA boxes
• AAAC motif
• I boxes
• Wound responsive elements
• ERE element -ethylene responsive element
• WUN motif - wound inducible element

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Questions?