1tkc: Difference between revisions

Revision as of 16:14, 21 February 2008

SPECIFICITY OF COENZYME BINDING IN THIAMIN DIPHOSPHATE DEPENDENT ENZYMES: CRYSTAL STRUCTURES OF YEAST TRANSKETOLASE IN COMPLEX WITH ANALOGS OF THIAMIN DIPHOSPHATE

OverviewOverview

The three-dimensional structures of complexes of yeast apotransketolase with the coenzyme analogs 6'-methyl, N1'-pyridyl, and N3'-pyridyl thiamin diphosphate, respectively, were determined with protein crystallographic methods. All three coenzyme analogs bind to the enzyme in a fashion highly similar to the cofactor thiamin diphosphate. Thus, either one of the hydrogen bonds of the pyrimidine ring nitrogens to the protein is sufficient for proper binding and positioning of the cofactor. The lack of catalytic activity of the N3'-pyridyl analog is not due to incorrect orientation of the pyrimidine ring, but results from the absence of the hydrogen bond between the N1' nitrogen atom and the conserved residue Glu418. The structure analysis provides further evidence for the importance of this conserved interaction for enzymatic thiamin catalysis.

About this StructureAbout this Structure

1TKC is a Single protein structure of sequence from Saccharomyces cerevisiae with and as ligands. Active as Transketolase, with EC number 2.2.1.1 Full crystallographic information is available from OCA.

ReferenceReference

Specificity of coenzyme binding in thiamin diphosphate-dependent enzymes. Crystal structures of yeast transketolase in complex with analogs of thiamin diphosphate., Konig S, Schellenberger A, Neef H, Schneider G, J Biol Chem. 1994 Apr 8;269(14):10879-82. PMID:8144674

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OCA

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-[[Image:1tkc.gif|left|200px]]<br /><applet load="1tkc" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1tkc.gif|left|200px]]<br /><applet load="1tkc" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1tkc, resolution 2.7&Aring;" />
 '''SPECIFICITY OF COENZYME BINDING IN THIAMIN DIPHOSPHATE DEPENDENT ENZYMES: CRYSTAL STRUCTURES OF YEAST TRANSKETOLASE IN COMPLEX WITH ANALOGS OF THIAMIN DIPHOSPHATE'''<br />
 ==Overview==
-The three-dimensional structures of complexes of yeast apotransketolase, with the coenzyme analogs 6'-methyl, N1'-pyridyl, and N3'-pyridyl thiamin, diphosphate, respectively, were determined with protein crystallographic, methods. All three coenzyme analogs bind to the enzyme in a fashion highly, similar to the cofactor thiamin diphosphate. Thus, either one of the, hydrogen bonds of the pyrimidine ring nitrogens to the protein is, sufficient for proper binding and positioning of the cofactor. The lack of, catalytic activity of the N3'-pyridyl analog is not due to incorrect, orientation of the pyrimidine ring, but results from the absence of the, hydrogen bond between the N1' nitrogen atom and the conserved residue, Glu418. The structure analysis provides further evidence for the, importance of this conserved interaction for enzymatic thiamin catalysis.
+The three-dimensional structures of complexes of yeast apotransketolase with the coenzyme analogs 6'-methyl, N1'-pyridyl, and N3'-pyridyl thiamin diphosphate, respectively, were determined with protein crystallographic methods. All three coenzyme analogs bind to the enzyme in a fashion highly similar to the cofactor thiamin diphosphate. Thus, either one of the hydrogen bonds of the pyrimidine ring nitrogens to the protein is sufficient for proper binding and positioning of the cofactor. The lack of catalytic activity of the N3'-pyridyl analog is not due to incorrect orientation of the pyrimidine ring, but results from the absence of the hydrogen bond between the N1' nitrogen atom and the conserved residue Glu418. The structure analysis provides further evidence for the importance of this conserved interaction for enzymatic thiamin catalysis.
 ==About this Structure==
-TKC is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae] with CA and M6T as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Transketolase Transketolase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.2.1.1 2.2.1.1] Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1TKC OCA].
+TKC is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae] with <scene name='pdbligand=CA:'>CA</scene> and <scene name='pdbligand=M6T:'>M6T</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Transketolase Transketolase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.2.1.1 2.2.1.1] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1TKC OCA].
 ==Reference==
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 [[Category: transferase]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Wed Nov 21 03:20:56 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:14:25 2008''