![]() They indicate that the metabolism of quinate ester and tyramine amide of p-coumaric acid rely on the same recognition site in the protein. Mammalian microsomal cytochrome P450 monooxygenase: Structural adaptations for membrane. Homology modeling, confirmed by directed mutagenesis, provides information on the protein regions and structural features important for some observed changes in substrate selectivity. Cytochromes P450 (CYP450s) are enzymes found in living organisms and play a crucial role in various biological processes, particularly in the metabolism of drugs and xenobiotics. ![]() One of the most significant is meta-hydroxylation of p-coumaroyltyramine, predominantly by the wheat enzymes, for the synthesis of suberin phenolic monomers. Some of them might be significant in the metabolism of various free or conjugated phenolics in different plant species. However, CYP98s from divergent taxa have acquired different additional subsidiary activities. 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. While ancient duplication led to evolution of enzymes with different substrate preferences, most of recent duplicates underwent silencing via degenerative mutations. Despite huge success in the field of genomics, proteomics and biotechnology, the function of many CYP members of plants is not yet known. Our results indicate that the unusually high frequency of gene duplication in the wheat CYP98 family is a direct or indirect result from ploidization. Comparison of the catalytic properties of the recombinant enzymes with those of CYP98s from other plant taxa was coupled to phylogenetic analyses. ![]() 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. Others, such as genes involved in the phenylpropanoid pathway have led to fewer duplication events. Cytochrome P450 proteins, named for the absorption band at 450 nm of their carbon-monoxide- bound form, are one of the largest superfamilies of enzyme proteins. This explosion of the P450 family is thought to have occurred via gene duplication and. Within this superfamily some clans and families are heavily duplicated. P450s thus form one of the largest families of proteins in higher plants. In eukaryotes, they are usually bound to the endoplasmic reticulum or inner mitochondrial membranes. In prokaryotes, P450s are soluble proteins. A burst of evolutionary duplication upon land colonization seems to have led to the large superfamily of cytochromes P450 in higher plants. In plants, chemical defense seems to be a major reason for P450 diversification.
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