Abstract
Aminoglycoside acetyltransferases (AACs) catalyze the transfer of an acetyl group between acetyl-CoA and an aminoglycoside, producing CoA and an acetylated aminoglycoside. AAC(6')-Ii enzymes target the amino group linked to the 6' C atom in an aminoglycoside. Several structures of the AAC(6')-Ii from Enterococcus faecium [Ef-AAC(6')-Ii] have been reported to date. However, the detailed mechanism of its enzymatic function remains elusive. In this study, the crystal structure of Ef-AAC(6')-Ii was determined in a novel substrate-free form. Based on structural analysis, it is proposed that Ef-AAC(6')-Ii sequentially undergoes conformational selection and induced fit for substrate binding. These results therefore provide a novel viewpoint on the mechanism of action of Ef-AAC(6')-Ii.
Keywords:
Enterococcus faecium; acetyl-CoA; aminoglycoside acetyltransferases; conformational selection; induced fit.
MeSH terms
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Acetyl Coenzyme A / chemistry*
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Acetyl Coenzyme A / metabolism
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Acetylation
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Acetyltransferases / chemistry*
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Acetyltransferases / genetics
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Acetyltransferases / metabolism
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Amino Acid Motifs
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Aminoglycosides / chemistry*
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Aminoglycosides / metabolism
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Bacterial Proteins / chemistry*
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Bacterial Proteins / genetics
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Bacterial Proteins / metabolism
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Binding Sites
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Cloning, Molecular
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Crystallography, X-Ray
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Enterococcus faecium / chemistry*
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Enterococcus faecium / enzymology
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Escherichia coli / genetics
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Escherichia coli / metabolism
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Gene Expression
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Genetic Vectors / chemistry
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Genetic Vectors / metabolism
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Models, Molecular
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Protein Binding
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Protein Conformation, alpha-Helical
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Protein Conformation, beta-Strand
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Protein Interaction Domains and Motifs
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Recombinant Proteins / chemistry
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Recombinant Proteins / genetics
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Recombinant Proteins / metabolism
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Substrate Specificity
Substances
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Aminoglycosides
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Bacterial Proteins
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Recombinant Proteins
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Acetyl Coenzyme A
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Acetyltransferases
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aminoglycoside N(6')-acetyltransferase