Cytochrome P-450-catalysed monoterpenoid oxidation in catmint (Nepeta racemosa)and avocado (Persea americana); evidence for related enzymes with different activities 

 -  Biochimica et Biophysica Acta, 1201(1), p.94-100, 1994 .
<br/><br/> A cytochrome P-450 present in ripening avocado (Persea americana)fruit mesocarp (CYTP71A1)had previously been shown to metabolize the monoterpenoids nerol and geraniol (Hallahan et al. (1992)Plant Physiol. 98, 1290-1297). Using DNA encoding CYP71A1 as a hybridization probe, we have shown by Southern analysis that a related gene is present in the catmint, Nepeta racemosa. RNA blot analysis, together with Western analysis of catmint leaf polypeptides using avocado cyt P-450 antiserum, showed that a closely related gene is expressed in catmint leaves. Cytochrome P-450 in catmint microsomes catalysed the specific hydroxylation of nerol and geraniol at C-10, whereas avocado CYP71A1, in either avocado microsomes or heterologously expressed in yeast, catalysed 2,3- or 6,7-epoxidation of these substrates. These results suggest that orthologous genes of the CYP71 family are expressed in these two plant species, but catalyse dissimilar reactions with monoterpenoid substrates. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>CYTOCHROME P-450<br/>PLANT ENZYME<br/>SUBSTRATE SPECIFICITY<br/>MONOTERPENOID<br/>GENES<br/>HYBRIDIZATION<br/>(N. RACEMOSA)<br/>(P. AMERICANA)