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Escherichia coli heptosyltransferase I: investigation of protein dynamics of a GT-B structural enzyme.

ABSTRACT: Heptosyltransferase I (HepI), the enzyme responsible for the transfer of l-glycero-d-manno-heptose to a 3-deoxy-?-d-manno-oct-2-ulopyranosonic acid (Kdo) of the growing core region of lipopolysaccharide, is a member of the GT-B structural class of enzymes. Crystal structures have revealed open and closed conformations of apo and ligand-bound GT-B enzymes, implying that large-scale protein conformational dynamics play a role in their reaction mechanism. Here we report transient kinetic analysis of conformational changes in HepI reported by intrinsic tryptophan fluorescence and present the first real-time evidence of a GT-B enzyme undergoing a substrate binding-induced transition from an open to closed state prior to catalysis.

SUBMITTER: Czyzyk DJ

PROVIDER: S-EPMC3867311 | biostudies-literature | 2013 Aug

REPOSITORIES: biostudies-literature

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Escherichia coli heptosyltransferase I: investigation of protein dynamics of a GT-B structural enzyme.

Czyzyk Daniel J DJ Sawant Shreya S SS Ramirez-Mondragon Carlos A CA Hingorani Manju M MM Taylor Erika A EA

Biochemistry 20130723 31

Heptosyltransferase I (HepI), the enzyme responsible for the transfer of l-glycero-d-manno-heptose to a 3-deoxy-α-d-manno-oct-2-ulopyranosonic acid (Kdo) of the growing core region of lipopolysaccharide, is a member of the GT-B structural class of enzymes. Crystal structures have revealed open and closed conformations of apo and ligand-bound GT-B enzymes, implying that large-scale protein conformational dynamics play a role in their reaction mechanism. Here we report transient kinetic analysis o ...[more]

PMID: 23865375

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The Stories Tryptophans Tell: Exploring Protein Dynamics of Heptosyltransferase I from Escherichia coli.

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