1mc3
From Proteopedia
(New page: 200px<br /><applet load="1mc3" size="450" color="white" frame="true" align="right" spinBox="true" caption="1mc3, resolution 2.6Å" /> '''CRYSTAL STRUCTURE OF ...) |
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| - | [[Image:1mc3.jpg|left|200px]]<br /><applet load="1mc3" size=" | + | [[Image:1mc3.jpg|left|200px]]<br /><applet load="1mc3" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1mc3, resolution 2.6Å" /> | caption="1mc3, resolution 2.6Å" /> | ||
'''CRYSTAL STRUCTURE OF RFFH'''<br /> | '''CRYSTAL STRUCTURE OF RFFH'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The enzyme glucose-1-phosphate thymidylyltransferase (RffH), the product | + | The enzyme glucose-1-phosphate thymidylyltransferase (RffH), the product of the rffh gene, catalyzes one of the steps in the synthesis of enterobacterial common antigen (ECA), a cell surface glycolipid found in Gram-negative enteric bacteria. In Escherichia coli two gene products, RffH and RmlA, catalyze the same enzymatic reaction and are homologous in sequence; however, they are part of different operons and function in different pathways. We report the crystal structure of RffH bound to deoxythymidine triphosphate (dTTP), the phosphate donor, and Mg(2+), refined at 2.6 A to an R-factor of 22.3% (R(free) = 28.4%). The crystal structure of RffH shows a tetrameric enzyme best described as a dimer of dimers. Each monomer has an overall alpha/beta fold and consists of two domains, a larger nucleotide binding domain (residues 1-115, 222-291) and a smaller sugar-binding domain (116-221), with the active site located at the domain interface. The Mg(2+) ion is coordinated by two conserved aspartates and the alpha-phosphate of deoxythymidine triphosphate. Its location corresponds well to that in a structurally similar domain of N-acetylglucosamine-1-phosphate uridylyltransferase (GlmU). Analysis of the RffH, RmlA, and GlmU complexes with substrates and products provides an explanation for their different affinities for Mg(2+) and leads to a proposal for the dynamics along the reaction pathway. |
==About this Structure== | ==About this Structure== | ||
| - | 1MC3 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with MG and TTP as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Glucose-1-phosphate_thymidylyltransferase Glucose-1-phosphate thymidylyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.7.24 2.7.7.24] Full crystallographic information is available from [http:// | + | 1MC3 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=MG:'>MG</scene> and <scene name='pdbligand=TTP:'>TTP</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Glucose-1-phosphate_thymidylyltransferase Glucose-1-phosphate thymidylyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.7.24 2.7.7.24] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1MC3 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Glucose-1-phosphate thymidylyltransferase]] | [[Category: Glucose-1-phosphate thymidylyltransferase]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: BSGI, Montreal-Kingston | + | [[Category: BSGI, Montreal-Kingston Bacterial Structural Genomics Initiative.]] |
[[Category: Cygler, M.]] | [[Category: Cygler, M.]] | ||
[[Category: Matte, A.]] | [[Category: Matte, A.]] | ||
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[[Category: structural genomics]] | [[Category: structural genomics]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:53:51 2008'' |
Revision as of 11:53, 21 February 2008
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CRYSTAL STRUCTURE OF RFFH
Overview
The enzyme glucose-1-phosphate thymidylyltransferase (RffH), the product of the rffh gene, catalyzes one of the steps in the synthesis of enterobacterial common antigen (ECA), a cell surface glycolipid found in Gram-negative enteric bacteria. In Escherichia coli two gene products, RffH and RmlA, catalyze the same enzymatic reaction and are homologous in sequence; however, they are part of different operons and function in different pathways. We report the crystal structure of RffH bound to deoxythymidine triphosphate (dTTP), the phosphate donor, and Mg(2+), refined at 2.6 A to an R-factor of 22.3% (R(free) = 28.4%). The crystal structure of RffH shows a tetrameric enzyme best described as a dimer of dimers. Each monomer has an overall alpha/beta fold and consists of two domains, a larger nucleotide binding domain (residues 1-115, 222-291) and a smaller sugar-binding domain (116-221), with the active site located at the domain interface. The Mg(2+) ion is coordinated by two conserved aspartates and the alpha-phosphate of deoxythymidine triphosphate. Its location corresponds well to that in a structurally similar domain of N-acetylglucosamine-1-phosphate uridylyltransferase (GlmU). Analysis of the RffH, RmlA, and GlmU complexes with substrates and products provides an explanation for their different affinities for Mg(2+) and leads to a proposal for the dynamics along the reaction pathway.
About this Structure
1MC3 is a Single protein structure of sequence from Escherichia coli with and as ligands. Active as Glucose-1-phosphate thymidylyltransferase, with EC number 2.7.7.24 Full crystallographic information is available from OCA.
Reference
Crystal structure of Escherichia coli glucose-1-phosphate thymidylyltransferase (RffH) complexed with dTTP and Mg2+., Sivaraman J, Sauve V, Matte A, Cygler M, J Biol Chem. 2002 Nov 15;277(46):44214-9. Epub 2002 Aug 8. PMID:12171937
Page seeded by OCA on Thu Feb 21 13:53:51 2008
Categories: Escherichia coli | Glucose-1-phosphate thymidylyltransferase | Single protein | BSGI, Montreal-Kingston Bacterial Structural Genomics Initiative. | Cygler, M. | Matte, A. | Sauve, V. | Sivaraman, J. | MG | TTP | Bsgi | Crystal structure | Glucose-1-phosphate thymidylytransferase | Montreal-kingston bacterial structural genomics initiative | Rffh | Structural genomics
