1i4z
From Proteopedia
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| - | + | {{STRUCTURE_1i4z| PDB=1i4z | SCENE= }} | |
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'''THE CRYSTAL STRUCTURE OF PHASCOLOPSIS GOULDII L98Y METHEMERYTHRIN''' | '''THE CRYSTAL STRUCTURE OF PHASCOLOPSIS GOULDII L98Y METHEMERYTHRIN''' | ||
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[[Category: Rose, J.]] | [[Category: Rose, J.]] | ||
[[Category: Wang, B C.]] | [[Category: Wang, B C.]] | ||
| - | [[Category: | + | [[Category: Diiron]] |
| - | [[Category: | + | [[Category: Four-helix bundle]] |
| - | [[Category: | + | [[Category: Hemerythrin]] |
| - | [[Category: | + | [[Category: Mutation]] |
| - | [[Category: | + | [[Category: Oxygen binding]] |
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 19:34:47 2008'' | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 16:34, 2 May 2008
THE CRYSTAL STRUCTURE OF PHASCOLOPSIS GOULDII L98Y METHEMERYTHRIN
Overview
Reported are the X-ray crystal structures of recombinant Phascolopsis gouldii methemerythrin (1.8-A resolution) and the structure of an O2-binding-pocket mutant, L98Y methemerythrin (2.1-A resolution). The L98Y hemerythrin (Hr) has a greatly enhanced O2 affinity, a slower O2 dissociation rate, a larger solvent deuterium isotope effect on this rate, and a greater resistance to autoxidation relative to the wild-type protein. The crystal structures show that the hydrophobic binding pocket of Hr can accommodate substitution of a leucyl by a tyrosyl side chain with relatively minor structural rearrangements. UV/vis and resonance Raman spectra show that in solution L98Y methemerythrin contains a mixture of two diiron site structures differing by the absence or presence of an Fe(III)-coordinated phenolate. However, in the crystal, only one L98Y diiron site structure is seen, in which the Y98 hydroxyl is not a ligand, but instead forms a hydrogen bond to a terminal hydroxo/aqua ligand to the nearest iron. Based on this crystal structure, we propose that in the oxy form of L98Y hemerythrin the non-polar nature of the binding pocket favors localization of the Y98 hydroxyl near the O2 binding site, where it can donate a hydrogen bond to the hydroperoxo ligand. The stabilizing Y98OH-O2H-interaction would account for all of the altered O2 binding properties of L98Y Hr listed above.
About this Structure
1I4Z is a Single protein structure of sequence from Phascolopsis gouldii. Full crystallographic information is available from OCA.
Reference
The crystal structures of Phascolopsis gouldii wild type and L98Y methemerythrins: structural and functional alterations of the O2 binding pocket., Farmer CS, Kurtz DM Jr, Liu ZJ, Wang BC, Rose J, Ai J, Sanders-Loehr J, J Biol Inorg Chem. 2001 Apr;6(4):418-29. PMID:11372200 Page seeded by OCA on Fri May 2 19:34:47 2008
