@article {Gang:2002p8027,
	title = {Characterization of phenylpropene O-methyltransferases from sweet basil: facile change of substrate specificity and convergent evolution within a plant O-methyltransferase family},
	journal = {Plant Cell},
	volume = {14},
	number = {2},
	year = {2002},
	month = {Feb},
	pages = {505{\textendash}19},
	abstract = {Some basil varieties are able to convert the phenylpropenes chavicol and eugenol to methylchavicol and methyleugenol, respectively. Chavicol O-methyltransferase (CVOMT) and eugenol O-methyltransferase (EOMT) cDNAs were isolated from the sweet basil variety EMX-1 using a biochemical genomics approach. These cDNAs encode proteins that are 90\% identical to each other and very similar to several isoflavone O-methyltransferases such as IOMT, which catalyzes the 4{\textquoteright}-O-methylation of 2,7,4{\textquoteright}-trihydroxyisoflavanone. On the other hand, CVOMT1 and EOMT1 are related only distantly to (iso)eugenol OMT from Clarkia breweri, indicating that the eugenol O-methylating enzymes in basil and C. breweri evolved independently. Transcripts for CVOMT1 and EOMT1 were highly expressed in the peltate glandular trichomes on the surface of the young basil leaves. The CVOMT1 and EOMT1 cDNAs were expressed in Escherichia coli, and active proteins were produced. CVOMT1 catalyzed the O-methylation of chavicol, and EOMT1 also catalyzed the O-methylation of chavicol with equal efficiency to that of CVOMT1, but it was much more efficient in O-methylating eugenol. Molecular modeling, based on the crystal structure of IOMT, suggested that a single amino acid difference was responsible for the difference in substrate discrimination between CVOMT1 and EOMT1. This prediction was confirmed by site-directed mutagenesis, in which the appropriate mutants of CVOMT1 (F260S) and EOMT1 (S261F) were produced that exhibited the opposite substrate preference relative to the respective native enzyme.},
	keywords = {Amino Acid Sequence, Anisoles, DNA: Complementary, Escherichia coli, Eugenol, Evolution: Molecular, Gene Expression, Gene Expression Regulation: Enzymologic, Gene Expression Regulation: Plant, Isoflavones, Methyltransferases, Molecular Sequence Data, Molecular Structure, Mutagenesis: Site-Directed, Mutation, Ocimum basilicum, Phylogeny, Recombinant Proteins, Sequence Homology: Amino Acid, Substrate Specificity},
	author = {David R Gang and Noa Lavid and Chloe Zubieta and Feng Chen and Till Beuerle and Efraim Lewinsohn and Joseph P Noel and Eran Pichersky}
}
@article {Kapteyn:2007p7982,
	title = {Evolution of Cinnamate/p-coumarate carboxyl methyltransferases and their role in the biosynthesis of methylcinnamate},
	journal = {Plant Cell},
	volume = {19},
	number = {10},
	year = {2007},
	month = {Oct},
	pages = {3212{\textendash}29},
	abstract = {Methylcinnamate, which is widely distributed throughout the plant kingdom, is a significant component of many floral scents and an important signaling molecule between plants and insects. Comparison of an EST database obtained from the glandular trichomes of a basil (Ocimum basilicum) variety that produces high levels of methylcinnamate (line MC) with other varieties producing little or no methylcinnamate identified several very closely related genes belonging to the SABATH family of carboxyl methyltransferases that are highly and almost exclusively expressed in line MC. Biochemical characterization of the corresponding recombinant proteins showed that cinnamate and p-coumarate are their best substrates for methylation, thus designating these enzymes as cinnamate/p-coumarate carboxyl methyltransferases (CCMTs). Gene expression, enzyme activity, protein profiling, and metabolite content analyses demonstrated that CCMTs are responsible for the formation of methylcinnamate in sweet basil. A phylogenetic analysis of the entire SABATH family placed these CCMTs into a clade that includes indole-3-acetic acid carboxyl methyltransferases and a large number of uncharacterized carboxyl methyltransferase-like proteins from monocots and lower plants. Structural modeling and ligand docking suggested active site residues that appear to contribute to the substrate preference of CCMTs relative to other members of the SABATH family. Site-directed mutagenesis of specific residues confirmed these findings.},
	keywords = {Amino Acid Sequence, Blotting: Southern, Cinnamates, Evolution: Molecular, Expressed Sequence Tags, Gas Chromatography-Mass Spectrometry, Gene Expression Profiling, Kinetics, Methylation, Methyltransferases, Models: Molecular, Molecular Sequence Data, Molecular Structure, Ocimum basilicum, Phylogeny, Plant Proteins, Protein Isoforms, Proteomics, Reverse Transcriptase Polymerase Chain Reaction, Sequence Homology: Amino Acid, Substrate Specificity},
	doi = {10.1105/tpc.107.054155},
	author = {Jeremy Kapteyn and Anthony V Qualley and Zhengzhi Xie and Eyal Fridman and Natalia Dudareva and David R Gang}
}
