Conformational Changes Induced by Binding UDP-2F-galactose to α-1,3 Galactosyltransferase- Implications for Catalysis

Jamaluddin, Haryati; Tumbale, Percy; Withers, Stephen G.; Acharya, K. Ravi; Brew, Keith

doi:10.1016/j.jmb.2007.04.012

Cited by 47 publications

(40 citation statements)

References 37 publications

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“…GT-A-fold-type enzymes have loops of polypeptide near the active site that have been observed to be disordered in the unliganded state, 7,9-11 which become ordered or undergo a conformational shift in GT-A-fold-type enzymes to cover the active site upon the binding of substrate. [12][13][14][15][16][17][18][19] We demonstrated previously that loops in GTA/GTB chimera (internal loop residues 177-195 and C-terminal tail residues 345-355) follow this paradigm, as they are normally disordered in the absence of substrate and gradually become more ordered as substrates are added to culminate in an enzyme that shows nearly complete order in the presence of donor and acceptor analogs. 9 The mobile loop participates in substrate recognition in GTA/ GTB 9 but has been suggested to function in GT-Afold-type enzymes in part by limiting the access of water molecules that may hydrolyze the nucleotide sugar donor.…”

Section: Introductionmentioning

confidence: 90%

Cysteine-to-Serine Mutants Dramatically Reorder the Active Site of Human ABO(H) Blood Group B Glycosyltransferase without Affecting Activity: Structural Insights into Cooperative Substrate Binding

Schuman

Persson

Landry

et al. 2010

Journal of Molecular Biology

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A common feature in the structures of GT-A-fold-type glycosyltransferases is a mobile polypeptide loop that has been observed to participate in substrate recognition and enclose the active site upon substrate binding. This is the case for the human ABO(H) blood group B glycosyltransferase GTB, where amino acid residues 177-195 display significantly higher levels of disorder in the unliganded state than in the fully liganded state. Structural studies of mutant enzymes GTB/C80S/C196S and GTB/C80S/C196S/C209S at resolutions ranging from 1.93 to 1.40 A display the opposite trend, where the unliganded structures show nearly complete ordering of the mobile loop residues that is lost upon substrate binding. In the liganded states of the mutant structures, while the UDP moiety of the donor molecule is observed to bind in the expected location, the galactose moiety is observed to bind in a conformation significantly different from that observed for the wild-type chimeric structures. Although this would be expected to impede catalytic turnover, the kinetics of the transfer reaction are largely unaffected. These structures demonstrate that the enzymes bind the donor in a conformation more similar to the dominant solution rotamer and facilitate its gyration into the catalytically competent form. Further, by preventing active-site closure, these structures provide a basis for recently observed cooperativity in substrate binding. Finally, the mutation of C80S introduces a fully occupied UDP binding site at the enzyme dimer interface that is observed to be dependent on the binding of H antigen acceptor analog.

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Section: Introductionmentioning

confidence: 90%

Cysteine-to-Serine Mutants Dramatically Reorder the Active Site of Human ABO(H) Blood Group B Glycosyltransferase without Affecting Activity: Structural Insights into Cooperative Substrate Binding

Schuman

Persson

Landry

et al. 2010

Journal of Molecular Biology

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“…In the case of retaining GTs, the Michaelis complex is actually a ternary complex, as two substrates are involved in the reaction (which usually follow a biordered mechanism). The donor substrate (UDP-monosaccharide for the systems reviewed here) binds first, sometimes accompanied by a conformational change linked to UDP binding; this is followed by the binding of the acceptor substrate, reaction, and product release (Boix et al, 2001;Jamaluddin, Tumbale, Withers, Acharya, & Brew, 2007;Lairson et al, 2008). Crystal structures of the enzyme with the hydrolyzed donor (i.e., enzyme:UDP) or inactive substrate analogues, the structure of the enzyme:UDP:acceptor or that of a mutated enzyme with the sugar donor substrate, are common for those systems.…”

Section: Model Preparation From the Crystallographic Datamentioning

confidence: 99%

QM/MM Studies Reveal How Substrate–Substrate and Enzyme–Substrate Interactions Modulate Retaining Glycosyltransferases Catalysis and Mechanism

Gómez

Mendoza

Lluch

et al. 2015

Advances in Protein Chemistry and Structural Biology

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“…More recently, Brew and coworkers [74] have described the crystal structure of a mutant form of α1,3GT (Arg365Lys) bound to a UDP-Gal inhibitory analogue, UDP-2F-Gal. The inhibitor is bound in a bent configuration to the mutant α1,3GT and conformational changes in the protein are observed when comparing the apo protein vs. the protein with UDP-2F-Gal bound.…”

Section: Structure Mechanism and Acceptor Substrate Specificity Of αmentioning

confidence: 99%

The Galα1,3Galβ1,4GlcNAc-R (α-Gal) epitope: A carbohydrate of unique evolution and clinical relevance

Macher

Galili

2008

Biochimica et Biophysica Acta (BBA) - General Subjects

368

337

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In 1985, we reported that a naturally occurring human antibody (anti-Gal), produced as the most abundant antibody (1% of immunoglobulins) throughout the life of all individuals, recognizes a carbohydrate epitope Galα1-3Galβ1-4GlcNAc-R (the α-gal epitope). Since that time, an extensive literature has developed on discoveries related to the α-gal epitope and the anti-Gal antibody, including the barrier they form in xenotransplantation and their reciprocity in mammalian evolution. This review covers these topics and new avenues of clinical importance related to this (α-gal epitope/ anti-Gal) unique antigen/antibody system in improving the efficacy of viral vaccines and in immunotherapy against cancer.

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Conformational Changes Induced by Binding UDP-2F-galactose to α-1,3 Galactosyltransferase- Implications for Catalysis

Cited by 47 publications

References 37 publications

Cysteine-to-Serine Mutants Dramatically Reorder the Active Site of Human ABO(H) Blood Group B Glycosyltransferase without Affecting Activity: Structural Insights into Cooperative Substrate Binding

Cysteine-to-Serine Mutants Dramatically Reorder the Active Site of Human ABO(H) Blood Group B Glycosyltransferase without Affecting Activity: Structural Insights into Cooperative Substrate Binding

QM/MM Studies Reveal How Substrate–Substrate and Enzyme–Substrate Interactions Modulate Retaining Glycosyltransferases Catalysis and Mechanism

The Galα1,3Galβ1,4GlcNAc-R (α-Gal) epitope: A carbohydrate of unique evolution and clinical relevance

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