@article {Willits:2004p8030,
	title = {Bio-fermentation of modified flavonoids: an example of in vivo diversification of secondary metabolites},
	journal = {Phytochemistry},
	volume = {65},
	number = {1},
	year = {2004},
	month = {Jan},
	pages = {31{\textendash}41},
	abstract = {A bio-fermentation technique was used for the in vivo diversification of flavonoid structures based on expression in Escherichia coli of six O-methyltransferases (OMTs) from Mentha x piperita and one O-glucosyltransferase (GT) each from Arabidopsis thaliana and Allium cepa. Enzymes were shown to be regio-specific in in vitro experiments and modified a broad range of flavonoid substrates at various positions. Using the flavonol quercetin as a model substrate, we show that the product spectrum produced with the in vivo approach is identical to that found in vitro. Additionally, using mixed cultures of E. coli expressing different classes of modifying genes (OMTs and GTs), the production of polymethylated flavonoid glucosides was observed. This report demonstrates the potential to increase the structural diversity of plant secondary metabolites using a multi-enzyme, bio-fermentation approach.},
	keywords = {Amino Acid Sequence, Arabidopsis, Cloning: Molecular, Consensus Sequence, Escherichia coli, Fermentation, Flavonoids, Glucosyltransferases, Mentha piperita, Methyltransferases, Molecular Sequence Data, Onions, Phylogeny, Recombinant Proteins, Sequence Alignment, Sequence Homology: Amino Acid, Stereoisomerism, Substrate Specificity},
	author = {Michael G Willits and Ma{\"{\i}t{\'e} Giovanni and Rogerio T N Prata and Catherine M Kramer and Vincenzo De Luca and John C Steffens and Gerson Graser}
}
@article {Yamazaki:1999p8037,
	title = {Molecular cloning and biochemical characterization of a novel anthocyanin 5-O-glucosyltransferase by mRNA differential display for plant forms regarding anthocyanin},
	journal = {J Biol Chem},
	volume = {274},
	number = {11},
	year = {1999},
	month = {Mar},
	pages = {7405{\textendash}11},
	abstract = {UDP-glucose: anthocyanin 5-O-glucosyltransferase (5-GT) is responsible for the modification of anthocyanins to more stable molecules in complexes for co-pigmentation, supposedly resulting in a purple hue. The cDNA encoding 5-GT was isolated by a differential display applied to two different forms of anthocyanin production in Perilla frutescens var. crispa. Differential display was carried out for mRNA from the leaves of reddish-purple and green forms of P. frutescens, resulting in the isolation of five cDNA clones predominantly expressed in the red form. The cDNA encoded a polypeptide of 460 amino acids, exhibiting a low homology with the sequences of several glucosyltransferases including UDP-glucose: anthocyanidin 3-O-glucosyltransferase. By using this cDNA as the probe, we also isolated a homologous cDNA clone from a petal cDNA library of Verbena hybrida. To identify the biochemical function of the encoded proteins, these cDNAs were expressed in Saccharomyces cerevisiae cells. The recombinant proteins in the yeast extracts catalyzed the conversion of anthocyanidin 3-O-glucosides into the corresponding anthocyanidin 3,5-di-O-glucosides using UDP-glucose as a cofactor, indicating the identity of the cDNAs encoding 5-GT. Several biochemical properties (optimum pH, Km values, and sensitivity to inhibitors) were similar to those reported previously for 5-GTs. Southern blot analysis indicated the presence of two copies of 5-GT genes in the genome of both red and green forms of P. frutescens. The mRNA accumulation of the 5-GT gene was detected in the leaves of the red form but not in those of the green form and was induced by illumination of light, as observed for other structural genes for anthocyanin biosynthesis in P. frutescens.},
	keywords = {Amino Acid Sequence, Anthocyanins, Cloning: Molecular, DNA: Complementary, Glucosyltransferases, Lamiaceae, Molecular Sequence Data, Phylogeny, Recombinant Proteins, RNA: Messenger, Saccharomyces cerevisiae, Sequence Homology: Amino Acid},
	author = {M Yamazaki and Z Gong and M Fukuchi-Mizutani and Y Fukui and Y Tanaka and T Kusumi and K Saito}
}
@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 {Lindqvist:2007p7988,
	title = {Polyglutamine variation in a flowering time protein correlates with island age in a Hawaiian plant radiation},
	journal = {BMC Evol Biol},
	volume = {7},
	year = {2007},
	month = {Jan},
	pages = {105},
	abstract = {BACKGROUND: A controversial topic in evolutionary developmental biology is whether morphological diversification in natural populations can be driven by expansions and contractions of amino acid repeats in proteins. To promote adaptation, selection on protein length variation must overcome deleterious effects of multiple correlated traits (pleiotropy). Thus far, systems that demonstrate this capacity include only ancient or artificial morphological diversifications. The Hawaiian Islands, with their linear geological sequence, present a unique environment to study recent, natural radiations. We have focused our research on the Hawaiian endemic mints (Lamiaceae), a large and diverse lineage with paradoxically low genetic variation, in order to test whether a direct relationship between coding-sequence repeat diversity and morphological change can be observed in an actively evolving system. RESULTS: Here we show that in the Hawaiian mints, extensive polyglutamine (CAG codon repeat) polymorphism within a homolog of the pleiotropic flowering time protein and abscisic acid receptor FCA tracks the natural environmental cline of the island chain, consequent with island age, across a period of 5 million years. CAG expansions, perhaps following their natural tendency to elongate, are more frequent in colonists of recently-formed, nutrient-rich islands than in their forebears on older, nutrient-poor islands. Values for several quantitative morphological variables related to reproductive investment, known from Arabidopsis fca mutant studies, weakly though positively correlate with increasing glutamine tract length. Together with protein modeling of FCA, which indicates that longer polyglutamine tracts could induce suboptimally mobile functional domains, we suggest that CAG expansions may form slightly deleterious alleles (with respect to protein function) that become fixed in founder populations. CONCLUSION: In the Hawaiian mint FCA system, we infer that contraction of slightly deleterious CAG repeats occurred because of competition for resources along the natural environmental cline of the island chain. The observed geographical structure of FCA variation and its correlation with morphologies expected from Arabidopsis mutant studies may indicate that developmental pleiotropy played a role in the diversification of the mints. This discovery is important in that it concurs with other suggestions that repetitive amino acid motifs might provide a mechanism for driving morphological evolution, and that variation at such motifs might permit rapid tuning to environmental change.},
	keywords = {Alleles, DNA: Plant, Genes: Plant, Hawaii, Mentha, Minisatellite Repeats, Peptides, Phylogeny, Plant Proteins, Selection: Genetic, Sequence Homology: Amino Acid, Species Specificity},
	doi = {10.1186/1471-2148-7-105},
	author = {Charlotte Lindqvist and Liisa Laakkonen and Victor A Albert}
}
@article {Iijima:2004p8022,
	title = {The biochemical and molecular basis for the divergent patterns in the biosynthesis of terpenes and phenylpropenes in the peltate glands of three cultivars of basil},
	journal = {Plant Physiol},
	volume = {136},
	number = {3},
	year = {2004},
	month = {Nov},
	pages = {3724{\textendash}36},
	abstract = {Surface glandular trichomes distributed throughout the aerial parts of sweet basil (Ocimum basilicum) produce and store monoterpene, sesquiterpene, and phenylpropene volatiles. Three distinct basil chemotypes were used to examine the molecular mechanisms underlying the divergence in their monoterpene and sesquiterpene content. The relative levels of specific terpenes in the glandular trichomes of each cultivar were correlated with the levels of transcripts for eight genes encoding distinct terpene synthases. In a cultivar that produces mostly (R)-linalool, transcripts of (R)-linalool synthase (LIS) were the most abundant of these eight. In a cultivar that synthesizes mostly geraniol, transcripts of geraniol synthase were the most abundant, but the glands of this cultivar also contained a transcript of an (R)-LIS gene with a 1-base insertion that caused a frameshift mutation. A geraniol synthase-LIS hybrid gene was constructed and expressed in Escherichia coli, and the protein catalyzed the formation of both geraniol and (R)-linalool from geranyl diphosphate. The total amounts of terpenes were correlated with total levels of terpene synthase activities, and negatively correlated with levels of phenylpropanoids and phenylalanine ammonia lyase activity. The relative levels of geranyl diphosphate synthase and farnesyl diphosphate synthase activities did not correlate with the total amount of terpenes produced, but showed some correlation with the ratio of monoterpenes to sesquiterpenes.},
	keywords = {Amino Acid Sequence, Gene Expression Regulation: Plant, Genetic Variation, Molecular Sequence Data, Molecular Structure, Ocimum basilicum, Phylogeny, Sequence Homology: Amino Acid, Styrenes, Terpenes},
	doi = {10.1104/pp.104.051318},
	author = {Yoko Iijima and Rachel Davidovich-Rikanati and Eyal Fridman and David R Gang and Einat Bar and Efraim Lewinsohn and Eran Pichersky}
}
@article {TapernouxLuthi:2004p8016,
	title = {Cloning, functional expression, and characterization of the raffinose oligosaccharide chain elongation enzyme, galactan:galactan galactosyltransferase, from common bugle leaves},
	journal = {Plant Physiol},
	volume = {134},
	number = {4},
	year = {2004},
	month = {Apr},
	pages = {1377{\textendash}87},
	abstract = {Galactan:galactan galactosyltransferase (GGT) is a unique enzyme of the raffinose family oligosaccharide (RFO) biosynthetic pathway. It catalyzes the chain elongation of RFOs without using galactinol (alpha-galactosyl-myoinositol) by simply transferring a terminal alpha-galactosyl residue from one RFO molecule to another one. Here, we report the cloning and functional expression of a cDNA encoding GGT from leaves of the common bugle (Ajuga reptans), a winter-hardy long-chain RFO-storing Lamiaceae. The cDNA comprises an open reading frame of 1215 bp. Expression in tobacco (Nicotiana plumbaginifolia) protoplasts resulted in a functional recombinant protein, which showed GGT activity like the previously described purified, native GGT enzyme. At the amino acid level, GGT shows high homologies (>60\%) to acid plant alpha-galactosidases of the family 27 of glycosylhydrolases. It is clearly distinct from the family 36 of glycosylhydrolases, which harbor galactinol-dependent raffinose and stachyose synthases as well as alkaline alpha-galactosidases. Physiological studies on the role of GGT confirmed that GGT plays a key role in RFO chain elongation and carbon storage. When excised leaves were exposed to chilling temperatures, levels of GGT transcripts, enzyme activities, and long-chain RFO concentrations increased concomitantly. On a whole-plant level, chilling temperatures induced GGT expression mainly in the roots and fully developed leaves, both known RFO storage organs of the common bugle, indicating an adaptation of the metabolism from active growth to transient storage in the cold.},
	keywords = {Ajuga, Amino Acid Sequence, Cloning: Molecular, Cold Temperature, DNA: Complementary, Galactosyltransferases, Gene Expression Regulation: Enzymologic, Gene Expression Regulation: Plant, Molecular Sequence Data, Phylogeny, Plant Leaves, Plant Proteins, Raffinose, Sequence Analysis: DNA, Sequence Homology: Amino Acid, Tobacco},
	doi = {10.1104/pp.103.036210},
	author = {Esther M Tapernoux-L{\"u}thi and Andreas B{\"o}hm and Felix Keller}
}
@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}
}
@article {Iijima:2004p8034,
	title = {Characterization of geraniol synthase from the peltate glands of sweet basil},
	journal = {Plant Physiol},
	volume = {134},
	number = {1},
	year = {2004},
	month = {Jan},
	pages = {370{\textendash}9},
	abstract = {The monoterpene fraction of the lemon-scented sweet basil (Ocimum basilicum) cv Sweet Dani consists mostly of citral (a mixture of geranial and neral), with lower levels of geraniol and nerol. These compounds are stored in the peltate glands found on the leaf epidermis. Younger leaves, which have a higher density of such glands, also have a higher content of monoterpenes than older leaves. Geraniol synthase (GES) activity, generating geraniol from geranyl diphosphate, was shown to be localized exclusively or almost exclusively to glands. GES activity resides in a homodimeric protein that was purified to near homogeneity. Basil GES requires Mn2+ as a divalent metal cofactor for activity and produces only geraniol from geranyl diphosphate. Km values of 21 and 51 microM were obtained for geranyl diphosphate and Mn2+, respectively. In the presence of 18O-labeled water, GES catalyzed the formation of 18O-geraniol from geranyl diphosphate, indicating that the reaction mechanism of GES is similar to that of other monoterpene synthases and is different from the action of phosphatases. A GES cDNA was isolated based on analysis of a glandular trichome expressed sequence tag database, and the sequence of the protein encoded by this cDNA shows some similarity to sequences of other terpene synthases. The expression of the GES cDNA in Escherichia coli resulted in a protein with enzymatic activity essentially identical to that of plant-purified GES. RNA gel-blot analysis indicated that GES is expressed in glands but not in leaves of basil cv Sweet Dani, whose glands contain geraniol and citral, and not in glands or leaves of another basil variety that makes other monoterpenes but not geraniol or citral.},
	keywords = {Alkyl and Aryl Transferases, Amino Acid Sequence, DNA: Complementary, DNA: Plant, Gene Expression, Genes: Plant, Molecular Sequence Data, Ocimum basilicum, Phylogeny, Plant Structures, Sequence Homology: Amino Acid, Terpenes},
	doi = {10.1104/pp.103.032946},
	author = {Yoko Iijima and David R Gang and Eyal Fridman and Efraim Lewinsohn and Eran Pichersky}
}
