A1 Refereed original research article in a scientific journal
Engineering a new magnesium binding site in the subunit contact region of Escherichia coli inorganic pyrophosphatase
Authors: Parfenyev AN, Salminen A, Baykov AA, Lahti R
Publisher: CONSULTANTS BUREAU
Publication year: 2000
Journal: Биохимия / Biochemistry
Journal name in source: BIOCHEMISTRY-MOSCOW
Journal acronym: BIOCHEMISTRY-MOSCOW+
Volume: 65
Issue: 3
First page : 388
Last page: 392
Number of pages: 5
ISSN: 0006-2979
Abstract
Three Gln-80 residues belonging to different subunits of homohexameric Escherichia coli pyrophosphatase are separated by only one water molecule to which they are hydrogen bonded. Substitution of Glu for Gln-80 stabilizes quaternary structure of the enzyme but has only a small effect on enzyme activity. The substitution stimulates Mg2+ binding and changes the appearance of the Mg2+ concentration dependence of the rate constant for the trimer --> hexamer transition. These data suggest that a new Mg2+ binding site is formed in the intersubunit contact region as a result of the substitution. Three-dimensional modeling of the mutated protein showed that a chelate complex might form involving two of the three Glu-80 residues.
Three Gln-80 residues belonging to different subunits of homohexameric Escherichia coli pyrophosphatase are separated by only one water molecule to which they are hydrogen bonded. Substitution of Glu for Gln-80 stabilizes quaternary structure of the enzyme but has only a small effect on enzyme activity. The substitution stimulates Mg2+ binding and changes the appearance of the Mg2+ concentration dependence of the rate constant for the trimer --> hexamer transition. These data suggest that a new Mg2+ binding site is formed in the intersubunit contact region as a result of the substitution. Three-dimensional modeling of the mutated protein showed that a chelate complex might form involving two of the three Glu-80 residues.
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