1la6
From Proteopedia
(New page: 200px<br /> <applet load="1la6" size="450" color="white" frame="true" align="right" spinBox="true" caption="1la6, resolution 2.0Å" /> '''The crystal structur...) |
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| - | [[Image:1la6.gif|left|200px]]<br /> | + | [[Image:1la6.gif|left|200px]]<br /><applet load="1la6" size="350" color="white" frame="true" align="right" spinBox="true" |
| - | <applet load="1la6" size=" | + | |
caption="1la6, resolution 2.0Å" /> | caption="1la6, resolution 2.0Å" /> | ||
'''The crystal structure of Trematomus newnesi hemoglobin in a partial hemichrome state'''<br /> | '''The crystal structure of Trematomus newnesi hemoglobin in a partial hemichrome state'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Tetrameric hemoglobins are the most widely used systems in studying | + | Tetrameric hemoglobins are the most widely used systems in studying protein cooperativity. Allosteric effects in hemoglobins arise from the switch between a relaxed (R) state and a tense (T) state occurring upon oxygen release. Here we report the 2.0-A crystal structure of the main hemoglobin component of the Antarctic fish Trematomus newnesi, in a partial hemichrome form. The two alpha-subunit iron atoms are bound to a CO molecule, whereas in the beta subunits the distal histidine residue is the sixth ligand of the heme iron. This structure, a tetrameric hemoglobin in the hemichrome state, demonstrates that the iron coordination by the distal histidine, usually associated with denaturing states, may be tolerated in a native-like hemoglobin structure. In addition, several features of the tertiary and quaternary organization of this structure are intermediate between the R and T states and agree well with the R --> T transition state properties obtained by spectroscopic and kinetic techniques. The analysis of this structure provides a detailed pathway of heme-heme communication and it indicates that the plasticity of the beta heme pocket plays a role in the R --> T transition of tetrameric hemoglobins. |
==About this Structure== | ==About this Structure== | ||
| - | 1LA6 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Trematomus_newnesi Trematomus newnesi] with ACE, HEM and CMO as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1LA6 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Trematomus_newnesi Trematomus newnesi] with <scene name='pdbligand=ACE:'>ACE</scene>, <scene name='pdbligand=HEM:'>HEM</scene> and <scene name='pdbligand=CMO:'>CMO</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1LA6 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Trematomus newnesi]] | [[Category: Trematomus newnesi]] | ||
[[Category: Mazzarella, L.]] | [[Category: Mazzarella, L.]] | ||
| - | [[Category: Prisco, G | + | [[Category: Prisco, G di.]] |
[[Category: Riccio, A.]] | [[Category: Riccio, A.]] | ||
[[Category: Vitagliano, L.]] | [[Category: Vitagliano, L.]] | ||
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[[Category: hemichrome]] | [[Category: hemichrome]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:43:00 2008'' |
Revision as of 11:43, 21 February 2008
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The crystal structure of Trematomus newnesi hemoglobin in a partial hemichrome state
Overview
Tetrameric hemoglobins are the most widely used systems in studying protein cooperativity. Allosteric effects in hemoglobins arise from the switch between a relaxed (R) state and a tense (T) state occurring upon oxygen release. Here we report the 2.0-A crystal structure of the main hemoglobin component of the Antarctic fish Trematomus newnesi, in a partial hemichrome form. The two alpha-subunit iron atoms are bound to a CO molecule, whereas in the beta subunits the distal histidine residue is the sixth ligand of the heme iron. This structure, a tetrameric hemoglobin in the hemichrome state, demonstrates that the iron coordination by the distal histidine, usually associated with denaturing states, may be tolerated in a native-like hemoglobin structure. In addition, several features of the tertiary and quaternary organization of this structure are intermediate between the R and T states and agree well with the R --> T transition state properties obtained by spectroscopic and kinetic techniques. The analysis of this structure provides a detailed pathway of heme-heme communication and it indicates that the plasticity of the beta heme pocket plays a role in the R --> T transition of tetrameric hemoglobins.
About this Structure
1LA6 is a Protein complex structure of sequences from Trematomus newnesi with , and as ligands. Full crystallographic information is available from OCA.
Reference
The crystal structure of a tetrameric hemoglobin in a partial hemichrome state., Riccio A, Vitagliano L, di Prisco G, Zagari A, Mazzarella L, Proc Natl Acad Sci U S A. 2002 Jul 23;99(15):9801-6. Epub 2002 Jul 1. PMID:12093902
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