1rks: Difference between revisions
New page: left|200px<br /><applet load="1rks" size="450" color="white" frame="true" align="right" spinBox="true" caption="1rks, resolution 2.4Å" /> '''E. COLI RIBOKINASE IN... |
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[[Image:1rks.jpg|left|200px]]<br /><applet load="1rks" size=" | [[Image:1rks.jpg|left|200px]]<br /><applet load="1rks" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="1rks, resolution 2.4Å" /> | caption="1rks, resolution 2.4Å" /> | ||
'''E. COLI RIBOKINASE IN COMPLEX WITH D-RIBOSE'''<br /> | '''E. COLI RIBOKINASE IN COMPLEX WITH D-RIBOSE'''<br /> | ||
==Overview== | ==Overview== | ||
The enzyme ribokinase phosphorylates ribose at O5* as the first step in | The enzyme ribokinase phosphorylates ribose at O5* as the first step in its metabolism. The original X-ray structure of Escherichia coli ribokinase represented the ternary complex including ribose and ADP. Structures are presented here for the apo enzyme, as well as the ribose-bound state and four new ternary complex forms. Combined, the structures suggest that large and small conformational changes play critical roles in the function of this kinase. An initially open apo form can allow entry of the ribose substrate. After ribose binding, the active site lid is observed in a closed conformation, with the sugar trapped underneath. This closure and associated changes in the protein appear to assist ribokinase in recognition of the co-substrate ATP as the next step. Binding of the nucleotide brings about further, less dramatic adjustments in the enzyme structure. Additional small movements are almost certainly required during the phosphoryltransfer reaction. Evidence is presented that some types of movements of the lid are allowed in the ternary complex, which may be critical to the creation and breakdown of the transition state. Similar events are likely to take place during catalysis by other related carbohydrate kinases, including adenosine kinase. | ||
==About this Structure== | ==About this Structure== | ||
1RKS 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 RIB and PO4 as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Ribokinase Ribokinase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.1.15 2.7.1.15] Full crystallographic information is available from [http:// | 1RKS 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=RIB:'>RIB</scene> and <scene name='pdbligand=PO4:'>PO4</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Ribokinase Ribokinase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.1.15 2.7.1.15] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1RKS OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: Ribokinase]] | [[Category: Ribokinase]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Cameron, A | [[Category: Cameron, A D.]] | ||
[[Category: Mowbray, S | [[Category: Mowbray, S L.]] | ||
[[Category: Sigrell, J | [[Category: Sigrell, J A.]] | ||
[[Category: PO4]] | [[Category: PO4]] | ||
[[Category: RIB]] | [[Category: RIB]] | ||
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[[Category: transferase]] | [[Category: transferase]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:51:55 2008'' | ||
Revision as of 15:51, 21 February 2008
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E. COLI RIBOKINASE IN COMPLEX WITH D-RIBOSE
OverviewOverview
The enzyme ribokinase phosphorylates ribose at O5* as the first step in its metabolism. The original X-ray structure of Escherichia coli ribokinase represented the ternary complex including ribose and ADP. Structures are presented here for the apo enzyme, as well as the ribose-bound state and four new ternary complex forms. Combined, the structures suggest that large and small conformational changes play critical roles in the function of this kinase. An initially open apo form can allow entry of the ribose substrate. After ribose binding, the active site lid is observed in a closed conformation, with the sugar trapped underneath. This closure and associated changes in the protein appear to assist ribokinase in recognition of the co-substrate ATP as the next step. Binding of the nucleotide brings about further, less dramatic adjustments in the enzyme structure. Additional small movements are almost certainly required during the phosphoryltransfer reaction. Evidence is presented that some types of movements of the lid are allowed in the ternary complex, which may be critical to the creation and breakdown of the transition state. Similar events are likely to take place during catalysis by other related carbohydrate kinases, including adenosine kinase.
About this StructureAbout this Structure
1RKS is a Single protein structure of sequence from Escherichia coli with and as ligands. Active as Ribokinase, with EC number 2.7.1.15 Full crystallographic information is available from OCA.
ReferenceReference
Induced fit on sugar binding activates ribokinase., Sigrell JA, Cameron AD, Mowbray SL, J Mol Biol. 1999 Jul 30;290(5):1009-18. PMID:10438599
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