Genes and enzymes involved in caffeic acid biosynthesis in the actinomycete Saccharothrix espanaensis.
The saccharomicins A and B, produced by the actinomycete Saccharothrix espanaensis, are oligosaccharide antibiotics. They consist of 17 monosaccharide units and the unique aglycon N-(m,p-dihydroxycinnamoyl)taurine. To investigate candidate genes responsible for the formation of trans-m,p-dihydroxycinnamic acid (caffeic acid) as part of the saccharomicin aglycon, gene expression experiments were carried out in Streptomyces fradiae XKS. It is shown that the biosynthetic pathway for trans-caffeic acid proceeds from L-tyrosine via trans-p-coumaric acid directly to trans-caffeic acid, since heterologous expression of sam8, encoding a tyrosine ammonia-lyase, led to the production of trans-p-hydroxycinnamic acid (coumaric acid), and coexpression of sam8 and sam5, the latter encoding a 4-coumarate 3-hydroxylase, led to the production of trans-m,p-dihydroxycinnamic acid. This is not in accordance with the general phenylpropanoid pathway in plants, where trans-p-coumaric acid is first activated before the 3-hydroxylation of its ring takes place.
Pharmazeutische Biologie und Biotechnologie, Institut für Pharmazeutische Wissenschaften, Albert-Ludwigs-Universität Freiburg im Breisgau, Stefan-Meier-Strasse 19 (VF), 79104 Freiburg, Germany.
Martin
M
Berner
Daniel
D
Krug
Corina
C
Bihlmaier
Andreas
A
Vente
Rolf
R
Müller
Andreas
A
Bechthold
D000192:Actinomycetales / Q000201:enzymology* / Q000235:genetics* / Q000378:metabolism; D002109:Caffeic Acids / Q000302:isolation & purification / Q000378:metabolism*; D002240:Carbohydrate Sequence; D003001:Cloning, Molecular; D005285:Fermentation; D015964:Gene Expression Regulation, Bacterial; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA
D002109:Caffeic Acids; C040048:caffeic acid