1la6
From Proteopedia
OCA (Talk | contribs)
(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...)
Next diff →
Revision as of 11:05, 8 November 2007
|
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 ACE, HEM and CMO 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
Page seeded by OCA on Thu Nov 8 13:11:33 2007
