1nsp
From Proteopedia
(New page: 200px<br /><applet load="1nsp" size="450" color="white" frame="true" align="right" spinBox="true" caption="1nsp, resolution 2.1Å" /> '''MECHANISM OF PHOSPHAT...) |
|||
| Line 1: | Line 1: | ||
| - | [[Image:1nsp.gif|left|200px]]<br /><applet load="1nsp" size=" | + | [[Image:1nsp.gif|left|200px]]<br /><applet load="1nsp" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1nsp, resolution 2.1Å" /> | caption="1nsp, resolution 2.1Å" /> | ||
'''MECHANISM OF PHOSPHATE TRANSFER BY NUCLEOSIDE DIPHOSPHATE KINASE: X-RAY STRUCTURES OF A PHOSPHO-HISTIDINE INTERMEDIATE OF THE ENZYMES FROM DROSOPHILA AND DICTYOSTELIUM'''<br /> | '''MECHANISM OF PHOSPHATE TRANSFER BY NUCLEOSIDE DIPHOSPHATE KINASE: X-RAY STRUCTURES OF A PHOSPHO-HISTIDINE INTERMEDIATE OF THE ENZYMES FROM DROSOPHILA AND DICTYOSTELIUM'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Nucleoside diphosphate kinase (NDP kinase) has a ping-pong mechanism with | + | Nucleoside diphosphate kinase (NDP kinase) has a ping-pong mechanism with a phosphohistidine intermediate. Crystals of the enzymes from Dictyostelium discoideum and from Drosophila melanogaster were treated with phosphoramidate, and their X-ray structures were determined at 2.1 and 2.2 A resolution, respectively. The atomic models, refined to R factors below 20%, show no conformation change relative to the free proteins. In both enzymes, the active site histidine was phosphorylated on N delta, and it was the only site of phosphorylation. The phosphate group interacts with the hydroxyl group of Tyr56 and with protein-bound water molecules. Its environment is compared with that of phosphohistidines in succinyl-CoA synthetase and in phosphocarrier proteins. The X-ray structures of phosphorylated NDP kinase and of previously determined complexes with nucleoside diphosphates provide a basis for modeling the Michaelis complex with a nucleoside triphosphate, that of the phosphorylated protein with a nucleoside diphosphate, and the transition state of the phosphate transfer reaction in which the gamma-phosphate is pentacoordinated. |
==About this Structure== | ==About this Structure== | ||
| - | 1NSP is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Dictyostelium_discoideum Dictyostelium discoideum]. Active as [http://en.wikipedia.org/wiki/Nucleoside-diphosphate_kinase Nucleoside-diphosphate kinase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.4.6 2.7.4.6] Full crystallographic information is available from [http:// | + | 1NSP is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Dictyostelium_discoideum Dictyostelium discoideum]. Active as [http://en.wikipedia.org/wiki/Nucleoside-diphosphate_kinase Nucleoside-diphosphate kinase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.4.6 2.7.4.6] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1NSP OCA]. |
==Reference== | ==Reference== | ||
| Line 21: | Line 21: | ||
[[Category: nucleoside triphosphate: nucleoside diphosphate]] | [[Category: nucleoside triphosphate: nucleoside diphosphate]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:09:37 2008'' |
Revision as of 12:09, 21 February 2008
|
MECHANISM OF PHOSPHATE TRANSFER BY NUCLEOSIDE DIPHOSPHATE KINASE: X-RAY STRUCTURES OF A PHOSPHO-HISTIDINE INTERMEDIATE OF THE ENZYMES FROM DROSOPHILA AND DICTYOSTELIUM
Overview
Nucleoside diphosphate kinase (NDP kinase) has a ping-pong mechanism with a phosphohistidine intermediate. Crystals of the enzymes from Dictyostelium discoideum and from Drosophila melanogaster were treated with phosphoramidate, and their X-ray structures were determined at 2.1 and 2.2 A resolution, respectively. The atomic models, refined to R factors below 20%, show no conformation change relative to the free proteins. In both enzymes, the active site histidine was phosphorylated on N delta, and it was the only site of phosphorylation. The phosphate group interacts with the hydroxyl group of Tyr56 and with protein-bound water molecules. Its environment is compared with that of phosphohistidines in succinyl-CoA synthetase and in phosphocarrier proteins. The X-ray structures of phosphorylated NDP kinase and of previously determined complexes with nucleoside diphosphates provide a basis for modeling the Michaelis complex with a nucleoside triphosphate, that of the phosphorylated protein with a nucleoside diphosphate, and the transition state of the phosphate transfer reaction in which the gamma-phosphate is pentacoordinated.
About this Structure
1NSP is a Single protein structure of sequence from Dictyostelium discoideum. Active as Nucleoside-diphosphate kinase, with EC number 2.7.4.6 Full crystallographic information is available from OCA.
Reference
Mechanism of phosphate transfer by nucleoside diphosphate kinase: X-ray structures of the phosphohistidine intermediate of the enzymes from Drosophila and Dictyostelium., Morera S, Chiadmi M, LeBras G, Lascu I, Janin J, Biochemistry. 1995 Sep 5;34(35):11062-70. PMID:7669763
Page seeded by OCA on Thu Feb 21 14:09:37 2008
