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2mas
From Proteopedia
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| - | [[Image:2mas.gif|left|200px]]<br /> | + | [[Image:2mas.gif|left|200px]]<br /><applet load="2mas" size="450" color="white" frame="true" align="right" spinBox="true" |
| - | <applet load="2mas" size="450" color="white" frame="true" align="right" spinBox="true" | + | |
caption="2mas, resolution 2.3Å" /> | caption="2mas, resolution 2.3Å" /> | ||
'''PURINE NUCLEOSIDE HYDROLASE WITH A TRANSITION STATE INHIBITOR'''<br /> | '''PURINE NUCLEOSIDE HYDROLASE WITH A TRANSITION STATE INHIBITOR'''<br /> | ||
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==About this Structure== | ==About this Structure== | ||
| - | 2MAS is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Crithidia_fasciculata Crithidia fasciculata] with CA and PIR as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Purine_nucleosidase Purine nucleosidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.2.1 3.2.2.1] | + | 2MAS is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Crithidia_fasciculata Crithidia fasciculata] with CA and PIR as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Purine_nucleosidase Purine nucleosidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.2.1 3.2.2.1] Known structural/functional Sites: <scene name='pdbsite=S1:Description Not Provided'>S1</scene>, <scene name='pdbsite=S2:Description Not Provided'>S2</scene>, <scene name='pdbsite=S3:Description Not Provided'>S3</scene> and <scene name='pdbsite=S4:Description Not Provided'>S4</scene>. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2MAS OCA]. |
==Reference== | ==Reference== | ||
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[[Category: uridine]] | [[Category: uridine]] | ||
| - | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Dec 18 20:12:51 2007'' |
Revision as of 18:03, 18 December 2007
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PURINE NUCLEOSIDE HYDROLASE WITH A TRANSITION STATE INHIBITOR
Overview
Nucleoside N-ribohydrolases are targets for disruption of purine salvage, in the protozoan parasites. The structure of a trypanosomal, N-ribohydrolase in complex with a transition-state inhibitor is reported, at 2.3 A resolution. The nonspecific nucleoside hydrolase from Crithidia, fasciculata cocrystallized with p-aminophenyliminoribitol reveals tightly, bound Ca2+ as a catalytic site ligand. The complex with the, transition-state inhibitor is characterized by (1) large protein, conformational changes to create a hydrophobic leaving group site (2), C3'-exo geometry for the inhibitor, typical of a ribooxocarbenium ion (3), stabilization of the ribooxocarbenium analogue between the neighboring, group 5'-hydroxyl and bidentate hydrogen bonds to Asn168; and (4), octacoordinate Ca2+ orients a catalytic site water and is liganded to two, hydroxyls of the inhibitor. The mechanism is ribooxocarbenium, stabilization with weak leaving group activation and is a departure from, glucohydrolases which use paired carboxylates to achieve the transition, state.
About this Structure
2MAS is a Single protein structure of sequence from Crithidia fasciculata with CA and PIR as ligands. Active as Purine nucleosidase, with EC number 3.2.2.1 Known structural/functional Sites: , , and . Full crystallographic information is available from OCA.
Reference
Trypanosomal nucleoside hydrolase. A novel mechanism from the structure with a transition-state inhibitor., Degano M, Almo SC, Sacchettini JC, Schramm VL, Biochemistry. 1998 May 5;37(18):6277-85. PMID:9572842
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