2h8f: Difference between revisions
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'''Crystal structure of deoxy hemoglobin from Trematomus bernacchii at pH 6.2''' | {{Structure | ||
|PDB= 2h8f |SIZE=350|CAPTION= <scene name='initialview01'>2h8f</scene>, resolution 1.30Å | |||
|SITE= | |||
|LIGAND= <scene name='pdbligand=ACE:ACETYL+GROUP'>ACE</scene> and <scene name='pdbligand=HEM:PROTOPORPHYRIN IX CONTAINING FE'>HEM</scene> | |||
|ACTIVITY= | |||
|GENE= | |||
}} | |||
'''Crystal structure of deoxy hemoglobin from Trematomus bernacchii at pH 6.2''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
2H8F is a [ | 2H8F is a [[Protein complex]] structure of sequences from [http://en.wikipedia.org/wiki/Trematomus_bernacchii Trematomus bernacchii]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2H8F OCA]. | ||
==Reference== | ==Reference== | ||
High resolution crystal structure of deoxy hemoglobin from Trematomus bernacchii at different pH values: the role of histidine residues in modulating the strength of the root effect., Mazzarella L, Vergara A, Vitagliano L, Merlino A, Bonomi G, Scala S, Verde C, di Prisco G, Proteins. 2006 Nov 1;65(2):490-8. PMID:[http:// | High resolution crystal structure of deoxy hemoglobin from Trematomus bernacchii at different pH values: the role of histidine residues in modulating the strength of the root effect., Mazzarella L, Vergara A, Vitagliano L, Merlino A, Bonomi G, Scala S, Verde C, di Prisco G, Proteins. 2006 Nov 1;65(2):490-8. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/16909420 16909420] | ||
[[Category: Protein complex]] | [[Category: Protein complex]] | ||
[[Category: Trematomus bernacchii]] | [[Category: Trematomus bernacchii]] | ||
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[[Category: root effect]] | [[Category: root effect]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 17:13:58 2008'' | ||
Revision as of 18:13, 20 March 2008
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| Coordinates: | save as pdb, mmCIF, xml | ||||||
Crystal structure of deoxy hemoglobin from Trematomus bernacchii at pH 6.2
OverviewOverview
The Root effect is a widespread property in fish hemoglobins (Hbs) that produces a drastic reduction of cooperativity and oxygen-binding ability at acidic pH. Here, we report the high-resolution structure of the deoxy form of Hb isolated from the Antarctic fish Trematomus bernacchii (HbTb) crystallized at pH 6.2 and 8.4. The structure at acidic pH has been previously determined at a moderate resolution (Ito et al., J Mol Biol 1995;250:648-658). Our results provide a clear picture of the events occurring upon the pH increase from 6.2 to 8.4, observed within a practically unchanged crystal environment. In particular, at pH 8.4, the interaspartic hydrogen bond at the alpha(1)beta(2) interface is partially broken, suggesting a pK(a) close to 8.4 for Asp95alpha. In addition, a detailed survey of the histidine modifications, caused by the change in pH, also indicates that at least three hot regions of the molecule are modified (Ebeta helix, Cbeta-tail, CDalpha corner) and can be considered to be involved at various levels in the release of the Root protons. Most importantly, at the CDalpha corner, the break of the salt bridge Asp48alpha-His55alpha allows us to describe a detailed mechanism that transmits the modification from the CDalpha corner far to the alpha heme. More generally, the results shed light on the role played by the histidine residues in modulating the strength of the Root effect and also support the emerging idea that the structural determinants, at least for a part of the Root effect, are specific of each Hb endowed with this property.
About this StructureAbout this Structure
2H8F is a Protein complex structure of sequences from Trematomus bernacchii. Full crystallographic information is available from OCA.
ReferenceReference
High resolution crystal structure of deoxy hemoglobin from Trematomus bernacchii at different pH values: the role of histidine residues in modulating the strength of the root effect., Mazzarella L, Vergara A, Vitagliano L, Merlino A, Bonomi G, Scala S, Verde C, di Prisco G, Proteins. 2006 Nov 1;65(2):490-8. PMID:16909420
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