1w1m
From Proteopedia
| Line 4: | Line 4: | ||
==Overview== | ==Overview== | ||
| - | The flavoenzyme vanillyl-alcohol oxidase was subjected to random | + | The flavoenzyme vanillyl-alcohol oxidase was subjected to random mutagenesis to generate mutants with enhanced reactivity to creosol (2-methoxy-4-methylphenol). The vanillyl-alcohol oxidase-mediated conversion of creosol proceeds via a two-step process in which the initially formed vanillyl alcohol (4-hydroxy-3-methoxybenzyl alcohol) is oxidized to the widely used flavor compound vanillin (4-hydroxy-3-methoxybenzaldehyde). The first step of this reaction is extremely slow due to the formation of a covalent FAD N-5-creosol adduct. After a single round of error-prone PCR, seven mutants were generated with increased reactivity to creosol. The single-point mutants I238T, F454Y, E502G, and T505S showed an up to 40-fold increase in catalytic efficiency (kcat/Km) with creosol compared with the wild-type enzyme. This enhanced reactivity was due to a lower stability of the covalent flavin-substrate adduct, thereby promoting vanillin formation. The catalytic efficiencies of the mutants were also enhanced for other ortho-substituted 4-methylphenols, but not for p-cresol (4-methylphenol). The replaced amino acid residues are not located within a distance of direct interaction with the substrate, and the determined three-dimensional structures of the mutant enzymes are highly similar to that of the wild-type enzyme. These results clearly show the importance of remote residues, not readily predicted by rational design, for the substrate specificity of enzymes. |
==About this Structure== | ==About this Structure== | ||
| Line 14: | Line 14: | ||
[[Category: Penicillium simplicissimum]] | [[Category: Penicillium simplicissimum]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Heuvel, R | + | [[Category: Heuvel, R H.Van Den.]] |
[[Category: EUG]] | [[Category: EUG]] | ||
[[Category: FAD]] | [[Category: FAD]] | ||
| Line 22: | Line 22: | ||
[[Category: oxidoreductase]] | [[Category: oxidoreductase]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:39:29 2008'' |
Revision as of 13:39, 21 February 2008
|
STRUCTURE OF THE OCTAMERIC FLAVOENZYME VANILLYL-ALCOHOL OXIDASE: GLU502GLY MUTANT
Overview
The flavoenzyme vanillyl-alcohol oxidase was subjected to random mutagenesis to generate mutants with enhanced reactivity to creosol (2-methoxy-4-methylphenol). The vanillyl-alcohol oxidase-mediated conversion of creosol proceeds via a two-step process in which the initially formed vanillyl alcohol (4-hydroxy-3-methoxybenzyl alcohol) is oxidized to the widely used flavor compound vanillin (4-hydroxy-3-methoxybenzaldehyde). The first step of this reaction is extremely slow due to the formation of a covalent FAD N-5-creosol adduct. After a single round of error-prone PCR, seven mutants were generated with increased reactivity to creosol. The single-point mutants I238T, F454Y, E502G, and T505S showed an up to 40-fold increase in catalytic efficiency (kcat/Km) with creosol compared with the wild-type enzyme. This enhanced reactivity was due to a lower stability of the covalent flavin-substrate adduct, thereby promoting vanillin formation. The catalytic efficiencies of the mutants were also enhanced for other ortho-substituted 4-methylphenols, but not for p-cresol (4-methylphenol). The replaced amino acid residues are not located within a distance of direct interaction with the substrate, and the determined three-dimensional structures of the mutant enzymes are highly similar to that of the wild-type enzyme. These results clearly show the importance of remote residues, not readily predicted by rational design, for the substrate specificity of enzymes.
About this Structure
1W1M is a Single protein structure of sequence from Penicillium simplicissimum with and as ligands. Active as Alcohol oxidase, with EC number 1.1.3.13 Known structural/functional Site: . Full crystallographic information is available from OCA.
Reference
Laboratory-evolved vanillyl-alcohol oxidase produces natural vanillin., van den Heuvel RH, van den Berg WA, Rovida S, van Berkel WJ, J Biol Chem. 2004 Aug 6;279(32):33492-500. Epub 2004 May 28. PMID:15169773
Page seeded by OCA on Thu Feb 21 15:39:29 2008
