2bh4
From Proteopedia
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==Overview== | ==Overview== | ||
| - | The structure of cytochrome c-550 from the nonphotosynthetic bacteria | + | The structure of cytochrome c-550 from the nonphotosynthetic bacteria Paraccocus versutus has been solved by X-ray crystallography to 1.90 A resolution, and reveals a high structural homology to other bacterial cytochromes c(2). The effect of replacing the axial heme-iron methionine ligand with a lysine residue on protein structure and unfolding has been assessed using the M100K variant. From X-ray structures at 1.95 and 1.55 A resolution it became clear that the amino group of the lysine side chain coordinates to the heme-iron. Structural differences compared to the wild-type protein are confined to the lysine ligand loop connecting helices four and five. In the heme cavity an additional water molecule is found which participates in an H-bonding interaction with the lysine ligand. Under cryo-conditions extra electron density in the lysine ligand loop is revealed, leading to residues K97 to T101 being modeled with a double main-chain conformation. Upon unfolding, dissociation of the lysine ligand from the heme-iron is shown to be pH dependent, with NMR data consistent with the occurrence of a ligand exchange mechanism similar to that seen for the wild-type protein. |
==About this Structure== | ==About this Structure== | ||
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[[Category: Paracoccus versutus]] | [[Category: Paracoccus versutus]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Canters, G | + | [[Category: Canters, G W.]] |
| - | [[Category: Roon, A | + | [[Category: Roon, A M.M Van.]] |
[[Category: Ubbink, M.]] | [[Category: Ubbink, M.]] | ||
| - | [[Category: Worrall, J | + | [[Category: Worrall, J A.R.]] |
[[Category: HEC]] | [[Category: HEC]] | ||
[[Category: axial ligand]] | [[Category: axial ligand]] | ||
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[[Category: pyrrolidone carboxylic acid]] | [[Category: pyrrolidone carboxylic acid]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:37:50 2008'' |
Revision as of 14:37, 21 February 2008
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X-RAY STRUCTURE OF THE M100K VARIANT OF FERRIC CYT C-550 FROM PARACOCCUS VERSUTUS DETERMINED AT 100 K.
Overview
The structure of cytochrome c-550 from the nonphotosynthetic bacteria Paraccocus versutus has been solved by X-ray crystallography to 1.90 A resolution, and reveals a high structural homology to other bacterial cytochromes c(2). The effect of replacing the axial heme-iron methionine ligand with a lysine residue on protein structure and unfolding has been assessed using the M100K variant. From X-ray structures at 1.95 and 1.55 A resolution it became clear that the amino group of the lysine side chain coordinates to the heme-iron. Structural differences compared to the wild-type protein are confined to the lysine ligand loop connecting helices four and five. In the heme cavity an additional water molecule is found which participates in an H-bonding interaction with the lysine ligand. Under cryo-conditions extra electron density in the lysine ligand loop is revealed, leading to residues K97 to T101 being modeled with a double main-chain conformation. Upon unfolding, dissociation of the lysine ligand from the heme-iron is shown to be pH dependent, with NMR data consistent with the occurrence of a ligand exchange mechanism similar to that seen for the wild-type protein.
About this Structure
2BH4 is a Single protein structure of sequence from Paracoccus versutus with as ligand. Known structural/functional Site: . Full crystallographic information is available from OCA.
Reference
The effect of replacing the axial methionine ligand with a lysine residue in cytochrome c-550 from Paracoccus versutus assessed by X-ray crystallography and unfolding., Worrall JA, van Roon AM, Ubbink M, Canters GW, FEBS J. 2005 May;272(10):2441-55. PMID:15885094
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