|
|
| (16 intermediate revisions not shown.) |
| Line 1: |
Line 1: |
| - | [[Image:2oc4.jpg|left|200px]]<br /><applet load="2oc4" size="350" color="white" frame="true" align="right" spinBox="true" | |
| - | caption="2oc4, resolution 2.592Å" /> | |
| - | '''Crystal stucture of human purine nucleoside phosphorylase mutant H257D with Imm-H'''<br /> | |
| | | | |
| - | ==Overview== | + | ==Crystal structure of human purine nucleoside phosphorylase mutant H257D with Imm-H== |
| - | The X-ray crystal structures of human purine nucleoside phosphorylase, (PNP) with bound inosine or transition-state analogues show His257 within, hydrogen bonding distance of the 5'-hydroxyl. The mutants His257Phe, His257Gly, and His257Asp exhibited greatly decreased affinity for, Immucillin-H (ImmH), binding this mimic of an early transition state as, much as 370-fold (Km/Ki) less tightly than native PNP. In contrast, these, mutants bound DADMe-ImmH, a mimic of a late transition state, nearly as, well as the native enzyme. These results indicate that His257 serves an, important role in the early stages of transition-state formation. Whereas, mutation of His257 resulted in little variation in the PNP.DADMe-ImmH.SO4, structures, His257Phe.ImmH.PO4 showed distortion at the 5'-hydroxyl, indicating the importance of H-bonding in positioning this group during, progression to the transition state. Binding isotope effect (BIE) and, kinetic isotope effect (KIE) studies of the remote 5'-3H for the, arsenolysis of inosine with native PNP revealed a BIE of 1.5% and an, unexpectedly large intrinsic KIE of 4.6%. This result is interpreted as a, moderate electronic distortion toward the transition state in the, Michaelis complex with continued development of a similar distortion at, the transition state. The mutants His257Phe, His257Gly, and His257Asp, altered the 5'-3H intrinsic KIE to -3, -14, and 7%, respectively, while, the BIEs contributed 2, 2, and -2%, respectively. These surprising results, establish that forces in the Michaelis complex, reported by the BIEs, can, be reversed or enhanced at the transition state. | + | <StructureSection load='2oc4' size='340' side='right'caption='[[2oc4]], [[Resolution|resolution]] 2.59Å' scene=''> |
| | + | == Structural highlights == |
| | + | <table><tr><td colspan='2'>[[2oc4]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2OC4 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2OC4 FirstGlance]. <br> |
| | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.592Å</td></tr> |
| | + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=IMH:1,4-DIDEOXY-4-AZA-1-(S)-(9-DEAZAHYPOXANTHIN-9-YL)-D-RIBITOL'>IMH</scene>, <scene name='pdbligand=PO4:PHOSPHATE+ION'>PO4</scene></td></tr> |
| | + | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=2oc4 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2oc4 OCA], [https://pdbe.org/2oc4 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2oc4 RCSB], [https://www.ebi.ac.uk/pdbsum/2oc4 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2oc4 ProSAT]</span></td></tr> |
| | + | </table> |
| | + | == Disease == |
| | + | [https://www.uniprot.org/uniprot/PNPH_HUMAN PNPH_HUMAN] Defects in PNP are the cause of purine nucleoside phosphorylase deficiency (PNPD) [MIM:[https://omim.org/entry/613179 613179]. It leads to a severe T-cell immunodeficiency with neurologic disorder in children.<ref>PMID:3029074</ref> <ref>PMID:1384322</ref> <ref>PMID:8931706</ref> |
| | + | == Function == |
| | + | [https://www.uniprot.org/uniprot/PNPH_HUMAN PNPH_HUMAN] The purine nucleoside phosphorylases catalyze the phosphorolytic breakdown of the N-glycosidic bond in the beta-(deoxy)ribonucleoside molecules, with the formation of the corresponding free purine bases and pentose-1-phosphate.<ref>PMID:2104852</ref> |
| | + | == Evolutionary Conservation == |
| | + | [[Image:Consurf_key_small.gif|200px|right]] |
| | + | Check<jmol> |
| | + | <jmolCheckbox> |
| | + | <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/oc/2oc4_consurf.spt"</scriptWhenChecked> |
| | + | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> |
| | + | <text>to colour the structure by Evolutionary Conservation</text> |
| | + | </jmolCheckbox> |
| | + | </jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=2oc4 ConSurf]. |
| | + | <div style="clear:both"></div> |
| | + | <div style="background-color:#fffaf0;"> |
| | + | == Publication Abstract from PubMed == |
| | + | The X-ray crystal structures of human purine nucleoside phosphorylase (PNP) with bound inosine or transition-state analogues show His257 within hydrogen bonding distance of the 5'-hydroxyl. The mutants His257Phe, His257Gly, and His257Asp exhibited greatly decreased affinity for Immucillin-H (ImmH), binding this mimic of an early transition state as much as 370-fold (Km/Ki) less tightly than native PNP. In contrast, these mutants bound DADMe-ImmH, a mimic of a late transition state, nearly as well as the native enzyme. These results indicate that His257 serves an important role in the early stages of transition-state formation. Whereas mutation of His257 resulted in little variation in the PNP x DADMe-ImmH x SO4 structures, His257Phe x ImmH x PO4 showed distortion at the 5'-hydroxyl, indicating the importance of H-bonding in positioning this group during progression to the transition state. Binding isotope effect (BIE) and kinetic isotope effect (KIE) studies of the remote 5'-(3)H for the arsenolysis of inosine with native PNP revealed a BIE of 1.5% and an unexpectedly large intrinsic KIE of 4.6%. This result is interpreted as a moderate electronic distortion toward the transition state in the Michaelis complex with continued development of a similar distortion at the transition state. The mutants His257Phe, His257Gly, and His257Asp altered the 5'-(3)H intrinsic KIE to -3, -14, and 7%, respectively, while the BIEs contributed 2, 2, and -2%, respectively. These surprising results establish that forces in the Michaelis complex, reported by the BIEs, can be reversed or enhanced at the transition state. |
| | | | |
| - | ==About this Structure==
| + | Neighboring group participation in the transition state of human purine nucleoside phosphorylase.,Murkin AS, Birck MR, Rinaldo-Matthis A, Shi W, Taylor EA, Almo SC, Schramm VL Biochemistry. 2007 May 1;46(17):5038-49. Epub 2007 Apr 4. PMID:17407325<ref>PMID:17407325</ref> |
| - | 2OC4 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with <scene name='pdbligand=PO4:'>PO4</scene> and <scene name='pdbligand=IMH:'>IMH</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Purine-nucleoside_phosphorylase Purine-nucleoside phosphorylase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.4.2.1 2.4.2.1] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2OC4 OCA].
| + | |
| | | | |
| - | ==Reference==
| + | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> |
| - | Neighboring Group Participation in the Transition State of Human Purine Nucleoside Phosphorylase., Murkin AS, Birck MR, Rinaldo-Matthis A, Shi W, Taylor EA Steven C Almo, Schramm VL, Biochemistry. 2007 May 1;46(17):5038-5049. Epub 2007 Apr 4. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17407325 17407325]
| + | </div> |
| - | [[Category: Homo sapiens]]
| + | <div class="pdbe-citations 2oc4" style="background-color:#fffaf0;"></div> |
| - | [[Category: Purine-nucleoside phosphorylase]]
| + | |
| - | [[Category: Single protein]]
| + | |
| - | [[Category: Almo, S.C.]]
| + | |
| - | [[Category: Rinaldo-Matthis, A.]]
| + | |
| - | [[Category: Schramm, V.L.]]
| + | |
| - | [[Category: IMH]]
| + | |
| - | [[Category: PO4]]
| + | |
| - | [[Category: purine nucleoside phosphorylase]]
| + | |
| | | | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Wed Jan 23 15:12:16 2008''
| + | ==See Also== |
| | + | *[[Purine nucleoside phosphorylase 3D structures|Purine nucleoside phosphorylase 3D structures]] |
| | + | == References == |
| | + | <references/> |
| | + | __TOC__ |
| | + | </StructureSection> |
| | + | [[Category: Homo sapiens]] |
| | + | [[Category: Large Structures]] |
| | + | [[Category: Almo SC]] |
| | + | [[Category: Rinaldo-Matthis A]] |
| | + | [[Category: Schramm VL]] |
| Structural highlights
Disease
PNPH_HUMAN Defects in PNP are the cause of purine nucleoside phosphorylase deficiency (PNPD) [MIM:613179. It leads to a severe T-cell immunodeficiency with neurologic disorder in children.[1] [2] [3]
Function
PNPH_HUMAN The purine nucleoside phosphorylases catalyze the phosphorolytic breakdown of the N-glycosidic bond in the beta-(deoxy)ribonucleoside molecules, with the formation of the corresponding free purine bases and pentose-1-phosphate.[4]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
The X-ray crystal structures of human purine nucleoside phosphorylase (PNP) with bound inosine or transition-state analogues show His257 within hydrogen bonding distance of the 5'-hydroxyl. The mutants His257Phe, His257Gly, and His257Asp exhibited greatly decreased affinity for Immucillin-H (ImmH), binding this mimic of an early transition state as much as 370-fold (Km/Ki) less tightly than native PNP. In contrast, these mutants bound DADMe-ImmH, a mimic of a late transition state, nearly as well as the native enzyme. These results indicate that His257 serves an important role in the early stages of transition-state formation. Whereas mutation of His257 resulted in little variation in the PNP x DADMe-ImmH x SO4 structures, His257Phe x ImmH x PO4 showed distortion at the 5'-hydroxyl, indicating the importance of H-bonding in positioning this group during progression to the transition state. Binding isotope effect (BIE) and kinetic isotope effect (KIE) studies of the remote 5'-(3)H for the arsenolysis of inosine with native PNP revealed a BIE of 1.5% and an unexpectedly large intrinsic KIE of 4.6%. This result is interpreted as a moderate electronic distortion toward the transition state in the Michaelis complex with continued development of a similar distortion at the transition state. The mutants His257Phe, His257Gly, and His257Asp altered the 5'-(3)H intrinsic KIE to -3, -14, and 7%, respectively, while the BIEs contributed 2, 2, and -2%, respectively. These surprising results establish that forces in the Michaelis complex, reported by the BIEs, can be reversed or enhanced at the transition state.
Neighboring group participation in the transition state of human purine nucleoside phosphorylase.,Murkin AS, Birck MR, Rinaldo-Matthis A, Shi W, Taylor EA, Almo SC, Schramm VL Biochemistry. 2007 May 1;46(17):5038-49. Epub 2007 Apr 4. PMID:17407325[5]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Williams SR, Gekeler V, McIvor RS, Martin DW Jr. A human purine nucleoside phosphorylase deficiency caused by a single base change. J Biol Chem. 1987 Feb 15;262(5):2332-8. PMID:3029074
- ↑ Aust MR, Andrews LG, Barrett MJ, Norby-Slycord CJ, Markert ML. Molecular analysis of mutations in a patient with purine nucleoside phosphorylase deficiency. Am J Hum Genet. 1992 Oct;51(4):763-72. PMID:1384322
- ↑ Pannicke U, Tuchschmid P, Friedrich W, Bartram CR, Schwarz K. Two novel missense and frameshift mutations in exons 5 and 6 of the purine nucleoside phosphorylase (PNP) gene in a severe combined immunodeficiency (SCID) patient. Hum Genet. 1996 Dec;98(6):706-9. PMID:8931706
- ↑ Ealick SE, Rule SA, Carter DC, Greenhough TJ, Babu YS, Cook WJ, Habash J, Helliwell JR, Stoeckler JD, Parks RE Jr, et al.. Three-dimensional structure of human erythrocytic purine nucleoside phosphorylase at 3.2 A resolution. J Biol Chem. 1990 Jan 25;265(3):1812-20. PMID:2104852
- ↑ Murkin AS, Birck MR, Rinaldo-Matthis A, Shi W, Taylor EA, Almo SC, Schramm VL. Neighboring group participation in the transition state of human purine nucleoside phosphorylase. Biochemistry. 2007 May 1;46(17):5038-49. Epub 2007 Apr 4. PMID:17407325 doi:10.1021/bi700147b
|
