Pesticide Science (1999) 55, 277-280

Douglas B. Jordan, Gregory S. Basarab, James J. Steffens, Tomas Lundqvist, Beverly R. Pfrogner, Rand S. Schwartz and Zdzislaw Wawrzak (1999)
Catalytic mechanism of scytalone dehydratase from Magnaporthe grisea
Pesticide Science 55 (3), 277-280
Abstract: The catalytic mechanism of scytalone dehydratase was examined by studying alternative substrates and site-directed mutations of active-site residues. Searches for an enol intermediate by looking for a half-reaction with authentic scytalone and 3,4-dihydro-6,8-dihydroxy-1-(2H)-2-[¹³C]naphthalenone were negative. An alternative substrate, 2,3-dihydro-2,5-dihydroxy-4H-benzopyran-4-one (DDBO), was nearly equal to scytalone as substrate for the enzyme, and DDBO's anomeric effect in stabilizing a partial carbocation center at C3 does not substantially contribute to the mechanism. Kinetic analysis of site-directed mutations of active-site amino acid side chains within the enzyme's active site provided an account for the role of these residues in the enzyme-catalyzed dehydration reactions. A concerted E2 elimination for the catalytic mechanism is proposed.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)

Research topic(s) for pests/diseases/weeds:
control - general
molecular biology - genes

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Pyricularia oryzae