Catalytic activity, duplication and evolution of the CYP98 cytochrome P450 family in wheat.
A burst of evolutionary duplication upon land colonization seems to have led to the large superfamily of cytochromes P450 in higher plants. Within this superfamily some clans and families are heavily duplicated. Others, such as genes involved in the phenylpropanoid pathway have led to fewer duplication events. Eight coding sequences belonging to the CYP98 family reported to catalyze the 3-hydroxylation step in this pathway were isolated from Triticum aestivum (wheat) and expressed in yeast. Comparison of the catalytic properties of the recombinant enzymes with those of CYP98s from other plant taxa was coupled to phylogenetic analyses. Our results indicate that the unusually high frequency of gene duplication in the wheat CYP98 family is a direct or indirect result from ploidization. While ancient duplication led to evolution of enzymes with different substrate preferences, most of recent duplicates underwent silencing via degenerative mutations. Three of the eight tested CYP98s from wheat have phenol meta-hydroxylase activity, with p-coumaroylshikimate being the primary substrate for all of these, as it is the case for CYP98s from sweet basil and Arabidopsis thaliana. However, CYP98s from divergent taxa have acquired different additional subsidiary activities. Some of them might be significant in the metabolism of various free or conjugated phenolics in different plant species. One of the most significant is meta-hydroxylation of p-coumaroyltyramine, predominantly by the wheat enzymes, for the synthesis of suberin phenolic monomers. Homology modeling, confirmed by directed mutagenesis, provides information on the protein regions and structural features important for some observed changes in substrate selectivity. They indicate that the metabolism of quinate ester and tyramine amide of p-coumaric acid rely on the same recognition site in the protein.
Morant
Marc
M
Department of Plant Stress Response, Institute of Plant Molecular Biology, CNRS-UPR 2357, Université Louis Pasteur, Centre National de la Recherche Scientifique, 67000, Strasbourg, France.
Schoch
Guillaume A
GA
Ullmann
Pascaline
P
Ertunç
Tanya
T
Little
Dawn
D
Olsen
Carl Erik
CE
Petersen
Maike
M
Negrel
Jonathan
J
Werck-Reichhart
Danièle
D
D000595:Amino Acid Sequence; D001483:Base Sequence; D002384:Catalysis; D003373:Coumaric Acids / Q000737:chemistry / Q000378:metabolism; D003577:Cytochrome P-450 Enzyme System / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D019143:Evolution, Molecular; D020440:Gene Duplication; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D008954:Models, Biological; D008958:Models, Molecular; D008969:Molecular Sequence Data; D015394:Molecular Structure; D016297:Mutagenesis, Site-Directed; D010636:Phenols / Q000737:chemistry / Q000378:metabolism; D010802:Phylogeny; D006109:Poaceae / Q000235:genetics; D011123:Polyploidy; D017433:Protein Structure, Secondary; D016415:Sequence Alignment; D040681:Structural Homology, Protein; D013379:Substrate Specificity; D014908:Triticum / Q000201:enzymology / Q000235:genetics*; D014439:Tyramine / Q000031:analogs & derivatives / Q000737:chemistry / Q000378:metabolism
D003373:Coumaric Acids; D007527:Isoenzymes; D010636:Phenols; C074004:feruloyltyramine; D003577:Cytochrome P-450 Enzyme System; C110890:cytochrome P-450 CYP98A1 (Sorghum bicolor); D014439:Tyramine