1iu5: Difference between revisions
New page: left|200px<br /><applet load="1iu5" size="450" color="white" frame="true" align="right" spinBox="true" caption="1iu5, resolution 1.50Å" /> '''X-ray Crystal Struct... |
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[[Image:1iu5.gif|left|200px]]<br /><applet load="1iu5" size=" | [[Image:1iu5.gif|left|200px]]<br /><applet load="1iu5" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="1iu5, resolution 1.50Å" /> | caption="1iu5, resolution 1.50Å" /> | ||
'''X-ray Crystal Structure of the rubredoxin mutant from Pyrococcus Furiosus'''<br /> | '''X-ray Crystal Structure of the rubredoxin mutant from Pyrococcus Furiosus'''<br /> | ||
==Overview== | ==Overview== | ||
A neutron diffraction study has been carried out at 1.6 A resolution on a | A neutron diffraction study has been carried out at 1.6 A resolution on a mutant rubredoxin from Pyrococcus furiosus using the BIX-3 single-crystal diffractometer at the JRR-3 reactor of the Japan Atomic Energy Research Institute. In order to study the unusual thermostability of rubredoxin from P. furiosus (an organism that grows optimally at 373 K), the hydrogen-bonding patterns were compared between the wild-type protein and a 'triple-mutant' variant. In this mutant protein, three residues were changed (Trp3-->Tyr3, Ile23-->Val23, Leu32-->Ile32) so that they are identical to those in a mesophilic rubredoxin from Clostridium pasteurianum. In the present study, some minor changes were found between the wild-type and mutant proteins in the hydrogen-bonding patterns of the Trp3/Tyr3 region. In this investigation, the H/D-exchange ratios in the protein were also studied. Because the target protein was soaked in D2O during the crystallization procedure, most of the N-H and O-H bonds have become deuterated, while essentially all of the C-H bonds have not. In particular, the H/D-exchange pattern of the N-H amide bonds of the protein backbone is of interest because it may contain some indirect information about the mechanism of unfolding of this small protein. The results are in broad agreement with those from solution NMR studies, which suggest that the backbone amide bonds near the four Cys residues of the FeS4 redox center are most resistant to H/D exchange. Finally, the detailed geometries of the water molecules of hydration around the rubredoxin molecule are also reported. The 1.6 A resolution of the present neutron structure determination has revealed a more detailed picture than previously available of some portions of the water structure, including ordered and disordered O-D bonds. Crystallographic details: space group P2(1)2(1)2(1) (orthorhombic), unit-cell parameters a = 34.48, b = 35.70, c = 43.16 A; final agreement factors R = 0.196 and Rfree = 0.230 for 19,384 observed and 6548 unique neutron reflections collected at room temperature; crystal size 4 mm3; a total of 423 non-H atoms, 290 H atoms and 88 D atoms were located in this study. | ||
==About this Structure== | ==About this Structure== | ||
1IU5 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pyrococcus_furiosus Pyrococcus furiosus] with FE and DOD as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | 1IU5 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pyrococcus_furiosus Pyrococcus furiosus] with <scene name='pdbligand=FE:'>FE</scene> and <scene name='pdbligand=DOD:'>DOD</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1IU5 OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: Pyrococcus furiosus]] | [[Category: Pyrococcus furiosus]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Adams, M | [[Category: Adams, M W.W.]] | ||
[[Category: Bau, R.]] | [[Category: Bau, R.]] | ||
[[Category: Chatake, T.]] | [[Category: Chatake, T.]] | ||
[[Category: Jenney, F | [[Category: Jenney, F E.]] | ||
[[Category: Kurihara, K.]] | [[Category: Kurihara, K.]] | ||
[[Category: Niimura, N.]] | [[Category: Niimura, N.]] | ||
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[[Category: thermostability]] | [[Category: thermostability]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:15:40 2008'' | ||
Revision as of 14:15, 21 February 2008
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X-ray Crystal Structure of the rubredoxin mutant from Pyrococcus Furiosus
OverviewOverview
A neutron diffraction study has been carried out at 1.6 A resolution on a mutant rubredoxin from Pyrococcus furiosus using the BIX-3 single-crystal diffractometer at the JRR-3 reactor of the Japan Atomic Energy Research Institute. In order to study the unusual thermostability of rubredoxin from P. furiosus (an organism that grows optimally at 373 K), the hydrogen-bonding patterns were compared between the wild-type protein and a 'triple-mutant' variant. In this mutant protein, three residues were changed (Trp3-->Tyr3, Ile23-->Val23, Leu32-->Ile32) so that they are identical to those in a mesophilic rubredoxin from Clostridium pasteurianum. In the present study, some minor changes were found between the wild-type and mutant proteins in the hydrogen-bonding patterns of the Trp3/Tyr3 region. In this investigation, the H/D-exchange ratios in the protein were also studied. Because the target protein was soaked in D2O during the crystallization procedure, most of the N-H and O-H bonds have become deuterated, while essentially all of the C-H bonds have not. In particular, the H/D-exchange pattern of the N-H amide bonds of the protein backbone is of interest because it may contain some indirect information about the mechanism of unfolding of this small protein. The results are in broad agreement with those from solution NMR studies, which suggest that the backbone amide bonds near the four Cys residues of the FeS4 redox center are most resistant to H/D exchange. Finally, the detailed geometries of the water molecules of hydration around the rubredoxin molecule are also reported. The 1.6 A resolution of the present neutron structure determination has revealed a more detailed picture than previously available of some portions of the water structure, including ordered and disordered O-D bonds. Crystallographic details: space group P2(1)2(1)2(1) (orthorhombic), unit-cell parameters a = 34.48, b = 35.70, c = 43.16 A; final agreement factors R = 0.196 and Rfree = 0.230 for 19,384 observed and 6548 unique neutron reflections collected at room temperature; crystal size 4 mm3; a total of 423 non-H atoms, 290 H atoms and 88 D atoms were located in this study.
About this StructureAbout this Structure
1IU5 is a Single protein structure of sequence from Pyrococcus furiosus with and as ligands. Full crystallographic information is available from OCA.
ReferenceReference
A neutron crystallographic analysis of a rubredoxin mutant at 1.6 A resolution., Chatake T, Kurihara K, Tanaka I, Tsyba I, Bau R, Jenney FE Jr, Adams MW, Niimura N, Acta Crystallogr D Biol Crystallogr. 2004 Aug;60(Pt 8):1364-73. Epub 2004, Jul 21. PMID:15272158
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