2mas: Difference between revisions
No edit summary |
No edit summary |
||
| Line 1: | Line 1: | ||
[[Image:2mas.gif|left|200px]]< | [[Image:2mas.gif|left|200px]] | ||
'''PURINE NUCLEOSIDE HYDROLASE WITH A TRANSITION STATE INHIBITOR''' | {{Structure | ||
|PDB= 2mas |SIZE=350|CAPTION= <scene name='initialview01'>2mas</scene>, resolution 2.3Å | |||
|SITE= <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> | |||
|LIGAND= <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene> and <scene name='pdbligand=PIR:2-(4-AMINO-PHENYL)-5-HYDROXYMETHYL-PYRROLIDINE-3,4-DIOL'>PIR</scene> | |||
|ACTIVITY= [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] | |||
|GENE= IU-NH FROM C. FASCICULATA ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=5656 Crithidia fasciculata]) | |||
}} | |||
'''PURINE NUCLEOSIDE HYDROLASE WITH A TRANSITION STATE INHIBITOR''' | |||
==Overview== | ==Overview== | ||
| Line 7: | Line 16: | ||
==About this Structure== | ==About this Structure== | ||
2MAS is a [ | 2MAS is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Crithidia_fasciculata Crithidia fasciculata]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2MAS OCA]. | ||
==Reference== | ==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:[http:// | 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:[http://www.ncbi.nlm.nih.gov/pubmed/9572842 9572842] | ||
[[Category: Crithidia fasciculata]] | [[Category: Crithidia fasciculata]] | ||
[[Category: Purine nucleosidase]] | [[Category: Purine nucleosidase]] | ||
| Line 26: | Line 35: | ||
[[Category: uridine]] | [[Category: uridine]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 17:46:54 2008'' | ||
Revision as of 18:46, 20 March 2008
| |||||||
| , resolution 2.3Å | |||||||
|---|---|---|---|---|---|---|---|
| Sites: | , , and | ||||||
| Ligands: | and | ||||||
| Gene: | IU-NH FROM C. FASCICULATA (Crithidia fasciculata) | ||||||
| Activity: | Purine nucleosidase, with EC number 3.2.2.1 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
PURINE NUCLEOSIDE HYDROLASE WITH A TRANSITION STATE INHIBITOR
OverviewOverview
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 StructureAbout this Structure
2MAS is a Single protein structure of sequence from Crithidia fasciculata. Full crystallographic information is available from OCA.
ReferenceReference
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
Page seeded by OCA on Thu Mar 20 17:46:54 2008