This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.

Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.

3dxf

From Proteopedia

(Difference between revisions)

Jump to: navigation, search

Revision as of 07:02, 19 August 2020

Crystal structure of the HSCARG R37A mutant

Structural highlights

3dxf is a 2 chain structure with sequence from Human. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Related:	2exx
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

[NMRL1_HUMAN] Redox sensor protein. Undergoes restructuring and subcellular redistribution in response to changes in intracellular NADPH/NADP(+) levels. At low NADPH concentrations the protein is found mainly as a monomer, and binds argininosuccinate synthase (ASS1), the enzyme involved in nitric oxide synthesis. Association with ASS1 impairs its activity and reduces the production of nitric oxide, which subsecuently prevents apoptosis. Under normal NADPH concentrations, the protein is found as a dimer and hides the binding site for ASS1. The homodimer binds one molecule of NADPH. Has higher affinity for NADPH than for NADP(+). Binding to NADPH is necessary to form a stable dimer.^[1] ^[2] ^[3]

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

NADP(H) is an important cofactor that controls many fundamental cellular processes. We have determined the crystal structure of HSCARG, a novel NADPH sensor, and found that it forms an asymmetrical dimer with only one subunit occupied by an NADPH molecule, and the two subunits have dramatically different conformations. To study the role of NADPH in affecting the structure and function of HSCARG, here, we constructed a series of HSCARG mutants to abolish NADPH binding ability. Protein structures of two mutants, R37A and Y81A, were solved by X-ray crystallography. The dimerization of wild-type and mutant HSCARG was studied by dynamic light scattering. Differences between the function of wild-type and mutant HSCARG were also compared. Our results show that binding of NADPH is necessary for HSCARG to form a stable asymmetric dimer. The conformation of the monomeric mutants was similar to that of NADPH-bound Molecule I in wild-type HSCARG, although some conformational changes were found in the NADPH binding site. Furthermore, we also noticed that abolition of NADPH binding ability changes the distribution of HSCARG in the cell and that these mutants without NADPH are more strongly associated with argininosuccinate synthetase as compared with wild-type HSCARG. These data suggest that NADPH functions as an allosteric regulator of the structure and function of HSCARG. In response to the changes in the NADPH/NADP(+) ratio within cells, HSCARG, as a redox sensor, associates and dissociates with NADPH to form a new dynamic equilibrium. This equilibrium, in turn, will tip the dimerization balance of the protein molecule and consequently controls the regulatory function of HSCARG.

NADPH is an allosteric regulator of HSCARG.,Dai X, Li Y, Meng G, Yao S, Zhao Y, Yu Q, Zhang J, Luo M, Zheng X J Mol Biol. 2009 Apr 17;387(5):1277-85. Epub 2009 Feb 28. PMID:19254724^[4]

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

References

↑ Zhao Y, Zhang J, Li H, Li Y, Ren J, Luo M, Zheng X. An NADPH sensor protein (HSCARG) down-regulates nitric oxide synthesis by association with argininosuccinate synthetase and is essential for epithelial cell viability. J Biol Chem. 2008 Apr 18;283(16):11004-13. doi: 10.1074/jbc.M708697200. Epub 2008, Feb 8. PMID:18263583 doi:http://dx.doi.org/10.1074/jbc.M708697200
↑ Zheng X, Dai X, Zhao Y, Chen Q, Lu F, Yao D, Yu Q, Liu X, Zhang C, Gu X, Luo M. Restructuring of the dinucleotide-binding fold in an NADP(H) sensor protein. Proc Natl Acad Sci U S A. 2007 May 22;104(21):8809-14. Epub 2007 May 11. PMID:17496144
↑ Dai X, Li Y, Meng G, Yao S, Zhao Y, Yu Q, Zhang J, Luo M, Zheng X. NADPH is an allosteric regulator of HSCARG. J Mol Biol. 2009 Apr 17;387(5):1277-85. Epub 2009 Feb 28. PMID:19254724 doi:10.1016/j.jmb.2009.02.049
↑ Dai X, Li Y, Meng G, Yao S, Zhao Y, Yu Q, Zhang J, Luo M, Zheng X. NADPH is an allosteric regulator of HSCARG. J Mol Biol. 2009 Apr 17;387(5):1277-85. Epub 2009 Feb 28. PMID:19254724 doi:10.1016/j.jmb.2009.02.049

1 Structural highlights
2 Function
3 Evolutionary Conservation
4 Publication Abstract from PubMed
5 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/3dxf"

@@ Line 1: / Line 1: @@
 ==Crystal structure of the HSCARG R37A mutant==
-<StructureSection load='3dxf' size='340' side='right' caption='[[3dxf]], [[Resolution|resolution]] 2.20&Aring;' scene=''>
+<StructureSection load='3dxf' size='340' side='right'caption='[[3dxf]], [[Resolution|resolution]] 2.20&Aring;' scene=''>
 == Structural highlights ==
-<table><tr><td colspan='2'>[[3dxf]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3DXF OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3DXF FirstGlance]. <br>
+<table><tr><td colspan='2'>[[3dxf]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3DXF OCA]. For a <b>guided tour on the structure components</b> use [http://proteopedia.org/fgij/fg.htm?mol=3DXF FirstGlance]. <br>
 </td></tr><tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[2exx|2exx]]</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=3dxf FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3dxf OCA], [http://pdbe.org/3dxf PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=3dxf RCSB], [http://www.ebi.ac.uk/pdbsum/3dxf PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=3dxf ProSAT]</span></td></tr>
+<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://proteopedia.org/fgij/fg.htm?mol=3dxf FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3dxf OCA], [http://pdbe.org/3dxf PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=3dxf RCSB], [http://www.ebi.ac.uk/pdbsum/3dxf PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=3dxf ProSAT]</span></td></tr>
 </table>
 == Function ==
@@ Line 33: / Line 33: @@
 </StructureSection>
 [[Category: Human]]
+[[Category: Large Structures]]
 [[Category: Dai, X]]
 [[Category: Li, Y]]

3dxf

From Proteopedia

Revision as of 07:02, 19 August 2020

Crystal structure of the HSCARG R37A mutant

Structural highlights

Function

Evolutionary Conservation

Publication Abstract from PubMed

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

Views

Personal tools

Navigation

Search

Toolbox