Metal-catalyzed Oxidation of Fe2+ Dehydrogenases: consensus target sequence between Propanediol Oxidoreductase of Escherichia Coli and alcohol dehydrogenase I1 of Zymomonas Mobilis

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1994Suggested citation
Cabiscol Català, Elisa;
Aguilar, Juan;
Ros Salvador, Joaquim;
.
(1994)
.
Metal-catalyzed Oxidation of Fe2+ Dehydrogenases: consensus target sequence between Propanediol Oxidoreductase of Escherichia Coli and alcohol dehydrogenase I1 of Zymomonas Mobilis.
Journal of Biological Chemistry, 1994, Vol. 269, núm. 9, p. 6592-6597.
http://hdl.handle.net/10459.1/56772.
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Show full item recordAbstract
We have studied two enzymes of a newly described
family of dehydrogenases with high sequence homology,
1,2-propanediol oxidoreductase of Escherichia coli
and alcohol dehydrogenase II of Zymomonas mobilis.
These enzymes perform their metabolic role under anaerobic
conditions; in the presence of oxygen, they
show a very similar inactivation pattern by a metalcatalyzed
oxidation system. Titration of histidine residues
with diethyl pyrocarbonate showed one histidine
residue less in the oxidized enzymes. Comparison of
subtilisin peptide maps of active and inactivated enzymes
showed a difference in one histidine-containing
peptide, the sequence of which is YNTPH277GVAN for
propanediol oxidoreductase and YNLPH277GV for alcohol
dehydrogenase 11. This histidine residue lies 10
residues away from a proposed metal-binding site,
H263XyXHa67, necessary to explain a site-specific free
radical mechanism. The three histidine residues here
described are strictly conserved in all enzymes of this
family. In this report we propose that histidine 277 is a
target for oxidation by a metal-catalyzed oxidation system
and that this modification leads to the irreversible
inactivation of both enzymes.