1e2n: Difference between revisions
New page: left|200px<br /><applet load="1e2n" size="450" color="white" frame="true" align="right" spinBox="true" caption="1e2n, resolution 2.2Å" /> '''HPT + HMTT'''<br /> ... |
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[[Image:1e2n.gif|left|200px]]<br /><applet load="1e2n" size=" | [[Image:1e2n.gif|left|200px]]<br /><applet load="1e2n" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="1e2n, resolution 2.2Å" /> | caption="1e2n, resolution 2.2Å" /> | ||
'''HPT + HMTT'''<br /> | '''HPT + HMTT'''<br /> | ||
==Overview== | ==Overview== | ||
The structure of Herpes simplex virus type 1 thymidine kinase (TK(HSV1)) | The structure of Herpes simplex virus type 1 thymidine kinase (TK(HSV1)) is known at high resolution in complex with a series of ligands and exhibits important structural similarities to the nucleoside monophosphate (NMP) kinase family, which are known to show large conformational changes upon binding of substrates. The effect of substrate binding on the conformation and structural stability of TK(HSV1), measured by thermal denaturation experiments, far-UV circular dichroism (CD) and fluorescence is described, and the results indicate that the conformation of the ligand-free TK(HSV1) is less ordered and less stable compared to the ligated enzyme. Furthermore, two crystal structures of TK(HSV1) in complex with two new ligands, HPT and HMTT, refined to 2.2 A are presented. Although TK(HSV1):HPT does not exhibit any significant deviations from the model of TK(HSV1):dT, the TK(HSV1):HMTT complex displays a unique conformationally altered active site resulting in a lowered thermal stability of this complex. Moreover, we show that binding affinity and binding mode of the ligand correlate with thermal stability of the complex. We use this correlation to propose a method to estimate binding constants for new TK(HSV1)substrates using thermal denaturation measurements monitored by CD spectroscopy. The kinetic and structural results of both test substrates HPT and HMTT show that the CD thermal denaturation system is very sensitive to conformational changes caused by unusual binding of a substrate analog. | ||
==About this Structure== | ==About this Structure== | ||
1E2N is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Human_herpesvirus_4 Human herpesvirus 4] with SO4 and RCA as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Thymidine_kinase Thymidine kinase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.1.21 2.7.1.21] Full crystallographic information is available from [http:// | 1E2N is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Human_herpesvirus_4 Human herpesvirus 4] with <scene name='pdbligand=SO4:'>SO4</scene> and <scene name='pdbligand=RCA:'>RCA</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Thymidine_kinase Thymidine kinase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.1.21 2.7.1.21] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1E2N OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: Thymidine kinase]] | [[Category: Thymidine kinase]] | ||
[[Category: Scapozza, L.]] | [[Category: Scapozza, L.]] | ||
[[Category: Schulz, G | [[Category: Schulz, G E.]] | ||
[[Category: Vogt, J.]] | [[Category: Vogt, J.]] | ||
[[Category: RCA]] | [[Category: RCA]] | ||
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[[Category: null]] | [[Category: null]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:23:05 2008'' | ||
Revision as of 13:23, 21 February 2008
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HPT + HMTT
OverviewOverview
The structure of Herpes simplex virus type 1 thymidine kinase (TK(HSV1)) is known at high resolution in complex with a series of ligands and exhibits important structural similarities to the nucleoside monophosphate (NMP) kinase family, which are known to show large conformational changes upon binding of substrates. The effect of substrate binding on the conformation and structural stability of TK(HSV1), measured by thermal denaturation experiments, far-UV circular dichroism (CD) and fluorescence is described, and the results indicate that the conformation of the ligand-free TK(HSV1) is less ordered and less stable compared to the ligated enzyme. Furthermore, two crystal structures of TK(HSV1) in complex with two new ligands, HPT and HMTT, refined to 2.2 A are presented. Although TK(HSV1):HPT does not exhibit any significant deviations from the model of TK(HSV1):dT, the TK(HSV1):HMTT complex displays a unique conformationally altered active site resulting in a lowered thermal stability of this complex. Moreover, we show that binding affinity and binding mode of the ligand correlate with thermal stability of the complex. We use this correlation to propose a method to estimate binding constants for new TK(HSV1)substrates using thermal denaturation measurements monitored by CD spectroscopy. The kinetic and structural results of both test substrates HPT and HMTT show that the CD thermal denaturation system is very sensitive to conformational changes caused by unusual binding of a substrate analog.
About this StructureAbout this Structure
1E2N is a Single protein structure of sequence from Human herpesvirus 4 with and as ligands. Active as Thymidine kinase, with EC number 2.7.1.21 Full crystallographic information is available from OCA.
ReferenceReference
The effect of substrate binding on the conformation and structural stability of Herpes simplex virus type 1 thymidine kinase., Wurth C, Kessler U, Vogt J, Schulz GE, Folkers G, Scapozza L, Protein Sci. 2001 Jan;10(1):63-73. PMID:11266595
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