1i13: Difference between revisions

From Proteopedia
Jump to navigation Jump to search
No edit summary
No edit summary
 
(5 intermediate revisions by the same user not shown)
Line 1: Line 1:
==ANALYSIS OF AN INVARIANT ASPARTIC ACID IN HPRTS-ALANINE MUTANT==
==ANALYSIS OF AN INVARIANT ASPARTIC ACID IN HPRTS-ALANINE MUTANT==
<StructureSection load='1i13' size='340' side='right' caption='[[1i13]], [[Resolution|resolution]] 1.84&Aring;' scene=''>
<StructureSection load='1i13' size='340' side='right'caption='[[1i13]], [[Resolution|resolution]] 1.84&Aring;' scene=''>
== Structural highlights ==
== Structural highlights ==
<table><tr><td colspan='2'>[[1i13]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Trypanosoma_cruzi Trypanosoma cruzi]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1I13 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1I13 FirstGlance]. <br>
<table><tr><td colspan='2'>[[1i13]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Trypanosoma_cruzi Trypanosoma cruzi]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1I13 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1I13 FirstGlance]. <br>
</td></tr><tr><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=7HP:7-HYDROXY-PYRAZOLO[4,3-D]PYRIMIDINE'>7HP</scene>, <scene name='pdbligand=FMT:FORMIC+ACID'>FMT</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=PRP:ALPHA-PHOSPHORIBOSYLPYROPHOSPHORIC+ACID'>PRP</scene><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]] 1.84&#8491;</td></tr>
<tr><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1tc2|1tc2]], [[1tc1|1tc1]], [[1i0l|1i0l]], [[1i0i|1i0i]], [[1i14|1i14]]</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=7HP:7-HYDROXY-PYRAZOLO[4,3-D]PYRIMIDINE'>7HP</scene>, <scene name='pdbligand=FMT:FORMIC+ACID'>FMT</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=PRP:ALPHA-PHOSPHORIBOSYLPYROPHOSPHORIC+ACID'>PRP</scene></td></tr>
<tr><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Hypoxanthine_phosphoribosyltransferase Hypoxanthine phosphoribosyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.4.2.8 2.4.2.8] </span></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=1i13 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1i13 OCA], [https://pdbe.org/1i13 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1i13 RCSB], [https://www.ebi.ac.uk/pdbsum/1i13 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1i13 ProSAT]</span></td></tr>
<tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1i13 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1i13 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1i13 RCSB], [http://www.ebi.ac.uk/pdbsum/1i13 PDBsum]</span></td></tr>
</table>
<table>
== Function ==
[https://www.uniprot.org/uniprot/Q4DRC4_TRYCC Q4DRC4_TRYCC]
== Evolutionary Conservation ==
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
Check<jmol>
   <jmolCheckbox>
   <jmolCheckbox>
     <scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/i1/1i13_consurf.spt"</scriptWhenChecked>
     <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/i1/1i13_consurf.spt"</scriptWhenChecked>
     <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
     <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
     <text>to colour the structure by Evolutionary Conservation</text>
     <text>to colour the structure by Evolutionary Conservation</text>
   </jmolCheckbox>
   </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/chain_selection.php?pdb_ID=2ata ConSurf].
</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=1i13 ConSurf].
<div style="clear:both"></div>
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
<div style="background-color:#fffaf0;">
Line 26: Line 28:
From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
</div>
<div class="pdbe-citations 1i13" style="background-color:#fffaf0;"></div>


==See Also==
==See Also==
*[[Phosphoribosyltransferase|Phosphoribosyltransferase]]
*[[Phosphoribosyltransferase 3D structures|Phosphoribosyltransferase 3D structures]]
== References ==
== References ==
<references/>
<references/>
__TOC__
__TOC__
</StructureSection>
</StructureSection>
[[Category: Hypoxanthine phosphoribosyltransferase]]
[[Category: Large Structures]]
[[Category: Trypanosoma cruzi]]
[[Category: Trypanosoma cruzi]]
[[Category: Canyuk, B.]]
[[Category: Canyuk B]]
[[Category: Eakin, A E.]]
[[Category: Eakin AE]]
[[Category: Focia, P J.]]
[[Category: Focia PJ]]
[[Category: Catalytic base]]
[[Category: Nucleotide metabolism]]
[[Category: Phosphoribosyltransferase]]
[[Category: Purine salvage]]
[[Category: Ternary complex]]
[[Category: Transferase]]

Latest revision as of 09:19, 9 August 2023

ANALYSIS OF AN INVARIANT ASPARTIC ACID IN HPRTS-ALANINE MUTANTANALYSIS OF AN INVARIANT ASPARTIC ACID IN HPRTS-ALANINE MUTANT

Structural highlights

1i13 is a 2 chain structure with sequence from Trypanosoma cruzi. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 1.84Å
Ligands:, , ,
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

Q4DRC4_TRYCC

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 role of an invariant aspartic acid (Asp137) in hypoxanthine phosphoribosyltransferases (HPRTs) was examined by site-directed and saturation mutagenesis, functional analysis, and X-ray crystallography using the HPRT from Trypanosoma cruzi. Alanine substitution (D137A) resulted in a 30-fold decrease of k(cat), suggesting that Asp137 participates in catalysis. Saturation mutagenesis was used to generate a library of mutant HPRTs with random substitutions at position 137, and active enzymes were identified by complementation of a bacterial purine auxotroph. Functional analyses of the mutants, including determination of steady-state kinetic parameters and pH-rate dependence, indicate that glutamic acid or glutamine can replace the wild-type aspartate. However, the catalytic efficiency and pH-rate profile for the structural isosteric mutant, D137N, were similar to the D137A mutant. Crystal structures of four of the mutant enzymes were determined in ternary complex with substrate ligands. Structures of the D137E and D137Q mutants reveal potential hydrogen bonds, utilizing several bound water molecules in addition to protein atoms, that position these side chains within hydrogen bond distance of the bound purine analogue, similar in position to the aspartate in the wild-type structure. The crystal structure of the D137N mutant demonstrates that the Asn137 side chain does not form interactions with the purine substrate but instead forms novel interactions that cause the side chain to adopt a nonfunctional rotamer. The results from these structural and functional analyses demonstrate that HPRTs do not require a general base at position 137 for catalysis. Instead, hydrogen bonding sufficiently stabilizes the developing partial positive charge at the N7-atom of the purine substrate in the transition-state to promote catalysis.

The role for an invariant aspartic acid in hypoxanthine phosphoribosyltransferases is examined using saturation mutagenesis, functional analysis, and X-ray crystallography.,Canyuk B, Focia PJ, Eakin AE Biochemistry. 2001 Mar 6;40(9):2754-65. PMID:11258886[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

See Also

References

  1. Canyuk B, Focia PJ, Eakin AE. The role for an invariant aspartic acid in hypoxanthine phosphoribosyltransferases is examined using saturation mutagenesis, functional analysis, and X-ray crystallography. Biochemistry. 2001 Mar 6;40(9):2754-65. PMID:11258886

1i13, resolution 1.84Å

Drag the structure with the mouse to rotate

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

OCA