Convergent evolution in the BAHD family of acyl transferases: identification and characterization of anthocyanin acyl transferases from Arabidopsis thaliana

Abstract

SummaryMembers of the BAHD family of plant acyl transferases are very versatile catalytically, and are thought to be able to evolve new substrate specificities rapidly. Acylation of anthocyanins occurs in many plant species and affects anthocyanin stability and light absorption in solution. The versatility of BAHD acyl transferases makes it difficult to identify genes encoding enzymes with defined substrate specificities on the basis of structural homology to genes of known catalytic function alone. Consequently, we have used a modification to standard functional genomics strategies, incorporating co-expression profiling with anthocyanin accumulation, to identify genes encoding three anthocyanin acyl transferases from Arabidopsis thaliana. We show that the activities of these enzymes influence the stability of anthocyanins at neutral pH, and some acylations also affect the anthocyanin absorption maxima. These properties make the BAHD acyl transferases suitable tools for engineering anthocyanins for an improved range of biotechnological applications.

Evolutionarily Distinct BAHD N-acyltransferases are Responsible for Natural Variation of Aromatic Amine Conjugates in Rice

“…The convergent evolution of BAHD enzymes has been reported, where spermidine acyltransferases from distinct subclades of the BAHD family exhibit similar biochemical function (Luo et al, 2007). Here, similar results were observed for the convergent evolution of putrescine acyltransferases ( Figure 4A).…”

Novel Hydroxycinnamoyl-Coenzyme A Quinate Transferase Genes from Artichoke Are Involved in the Synthesis of Chlorogenic Acid

“…The acyl donors and acyl acceptors used as substrates by BAHD acyltransferases are diverse, and different BAHD family members show a range of substrate specificities. Similar substrate specificity may have evolved independently in different species for some BAHD acyltransferases; therefore, experimental validation tests are needed to definitively identify acyltransferase function (D'Auria, 2006;Luo et al, 2007). Enzymes with HQT activity and showing a preference for quinate over shikimate as acyl acceptor cluster together in phylogenetic trees and are clearly distinct from HCT enzymes, which generally prefer shikimate to quinate as an acyl acceptor and are thought to work principally in lignin biosynthesis (Hoffmann et al, 2003(Hoffmann et al, , 2004Sullivan, 2009).…”

“…The hqt1 and hqt2 cDNAs were recombined into the expression vector pJAM1784 (Luo et al, 2007) to allow expression, in E. coli, of recombinant S-tag fusion proteins under the control of the T7 promoter. The S-tag was used to confirm the production of fusion proteins of approximately 50 kD (Supplemental Fig.…”

“…The entry clones (pDONR207-hqt1 and pDONR207-hqt2) were obtained through recombination of the PCR products with pDONR207 (Invitrogen). Error-free clones were then introduced into the Gateway-compatible S-tag vector pJAM1784 (Luo et al, 2007) to produce the expression vectors pJAM1784-hqt1 and pJAM1784-hqt2. Recombinant proteins with an N-terminal S-tag were expressed in E. coli BL-21 Rosetta cells.…”

Comprehensive Flavonol Profiling and Transcriptome Coexpression Analysis Leading to Decoding Gene–Metabolite Correlations inArabidopsis

“…Thirty-five flavonoid biosynthetic genes, including genes encoding 12 transcription factors, 10 structural enzymes, and 10 modification enzymes, have been identified (Tohge et al, 2005Lepiniec et al, 2006;Fraser et al, 2007;Luo et al, 2007;Stracke et al, 2007;Yonekura-Sakakibara et al, 2007), but even in this highly studied species, the full details of the flavonoid pathway, including modification, are still unknown. The major flavonoid structures in Arabidopsis suggest that there are as yet unidentified modification enzyme genes and pathways in flavonoid metabolism.…”