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4kh4

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Revision as of 09:27, 5 August 2016

Toxoplasma gondii NTPDase1 C258S/C268S in complex with Mg and AMPPNP

Structural highlights

4kh4 is a 2 chain structure with sequence from Toxgo. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Ligands:	,
Related:	4a57, 4a59, 4a5a, 4a5b, 4jep, 4kh5, 4kh6
Gene:	NTP1 (TOXGO)
Activity:	Nucleoside-triphosphatase, with EC number 3.6.1.15
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

[NTP2_TOXGO] May perform an important processing step in the conversion of high energy nucleotides prior to uptake by the parasite. NTPAse-II has a specific activity 4.5-fold lower than NTPAse-I in hydrolysis of ATP. The primary difference between these isozymes lies in their ability to hydrolyze nucleoside triphosphate versus diphosphate substrates. While NTPAse-II hydrolyzes ATP to ADP and ADP to AMP at almost the same rate, NTPAse-I hydrolyzes ADP to AMP at a much slower rate (0.7% of the rate for ATP).

Publication Abstract from PubMed

Two nucleoside triphosphate diphosphohydrolase isoforms (NTPDase1 and NTPDase3) are responsible for the hydrolysis of nucleotides by the intracellular protozoan Toxoplasma gondii. They constitute about 3 % of the total parasite protein. Despite sharing 97 % sequence identity they exhibit opposite ATP versus ADP substrate discrimination ratios. Here we show by mutagenesis that the residues G492/G493 in NTPDase3 and R492/E493 in NTPDase1 are predominantly responsible for the differences in substrate specificity. Crystal structures of NTPDase1 in complexation with analogues of ATP and ADP reveal that the inverted substrate specificity of NTPDase1 relative to NTPDase3 is achieved by switching from the canonical substrate binding mode to a very different alternative one. Instead of being stacked on top of a helix of the C-terminal domain the nucleotide base is positioned in the interdomain space between the side chains of R108 and R492, recruited from both domains. Furthermore, we show that the NTPDase1 substrate specificity is mainly dependent on the presence of the side chain of E493, which causes repositioning of the ribose component of the nucleotide. All in all, binding by the flexible side chains in the alternative binding mode in NTPDase1 allows for equally good positioning of ATP and ADP with increased activity toward ADP relative to what is seen in the case of NTPDase3.

The ATP/ADP Substrate Specificity Switch between Toxoplasma gondii NTPDase1 and NTPDase3 is Caused by an Altered Mode of Binding of the Substrate Base.,Krug U, Totzauer R, Zebisch M, Strater N Chembiochem. 2013 Oct 2. doi: 10.1002/cbic.201300441. PMID:24115522^[1]

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

References

↑ Krug U, Totzauer R, Zebisch M, Strater N. The ATP/ADP Substrate Specificity Switch between Toxoplasma gondii NTPDase1 and NTPDase3 is Caused by an Altered Mode of Binding of the Substrate Base. Chembiochem. 2013 Oct 2. doi: 10.1002/cbic.201300441. PMID:24115522 doi:http://dx.doi.org/10.1002/cbic.201300441

1 Structural highlights
2 Function
3 Publication Abstract from PubMed
4 See Also
5 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/4kh4"

@@ Line 1: / Line 1: @@
 ==Toxoplasma gondii NTPDase1 C258S/C268S in complex with Mg and AMPPNP==
 <StructureSection load='4kh4' size='340' side='right' caption='[[4kh4]], [[Resolution|resolution]] 3.00&Aring;' scene=''>
@@ Line 7: / Line 8: @@
 <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">NTP1 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=5811 TOXGO])</td></tr>
 <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Nucleoside-triphosphatase Nucleoside-triphosphatase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.6.1.15 3.6.1.15] </span></td></tr>
-<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4kh4 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4kh4 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4kh4 RCSB], [http://www.ebi.ac.uk/pdbsum/4kh4 PDBsum]</span></td></tr>
+<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4kh4 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4kh4 OCA], [http://pdbe.org/4kh4 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4kh4 RCSB], [http://www.ebi.ac.uk/pdbsum/4kh4 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=4kh4 ProSAT]</span></td></tr>
 </table>
 == Function ==
@@ Line 19: / Line 20: @@
 From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
 </div>
+<div class="pdbe-citations 4kh4" style="background-color:#fffaf0;"></div>
 ==See Also==

4kh4

From Proteopedia

Revision as of 09:27, 5 August 2016

Toxoplasma gondii NTPDase1 C258S/C268S in complex with Mg and AMPPNP

Structural highlights

Function

Publication Abstract from PubMed

See Also

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

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