1e8e: Difference between revisions
New page: left|200px<br /><applet load="1e8e" size="450" color="white" frame="true" align="right" spinBox="true" caption="1e8e" /> '''SOLUTION STRUCTURE OF METHYLOPHILUS METHYLOT... |
No edit summary |
||
| Line 1: | Line 1: | ||
[[Image:1e8e.gif|left|200px]]<br /><applet load="1e8e" size=" | [[Image:1e8e.gif|left|200px]]<br /><applet load="1e8e" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="1e8e" /> | caption="1e8e" /> | ||
'''SOLUTION STRUCTURE OF METHYLOPHILUS METHYLOTROPHUS CYTOCHROME C''. INSIGHTS INTO THE STRUCTURAL BASIS OF HAEM-LIGAND DETACHMENT'''<br /> | '''SOLUTION STRUCTURE OF METHYLOPHILUS METHYLOTROPHUS CYTOCHROME C''. INSIGHTS INTO THE STRUCTURAL BASIS OF HAEM-LIGAND DETACHMENT'''<br /> | ||
==Overview== | ==Overview== | ||
Cytochrome c" from Methylophilus methylotrophus is a monohaem protein with | Cytochrome c" from Methylophilus methylotrophus is a monohaem protein with 124 amino acid residues. The iron has two histidine ligands in the oxidised form, one of which detaches and picks up a proton when the protein is reduced. Thus, both forms are paramagnetic. The structure of the oxidised form in solution, determined from NMR data is presented. The family of structures has an average backbone rmsd value of 0.53 A, and a heavy atom rmsd value of 0.95 A, within a target function range of 32 %. This structure is related to class I cytochromes with an additional helix at the N terminus. The haem-binding site occurs in a domain essentially lacking secondary structure motifs and the axial histidinyl residues were found in an unusual near perpendicular orientation. Moreover, a disulfide bridge is present, an uncommon structural feature among c-type cytochromes. The disulfide bridge, linking cysteine residues 96 and 104, forms a loop that confers rigidity and is essential to the detachment of the axial histidine (His95) as demonstrated by chemical disruption of the S-S bond. A route for protonation of the distal histidine involving haem propionate 17 is proposed and discussed in the light of available models for complex membrane proton pumps. | ||
==About this Structure== | ==About this Structure== | ||
1E8E is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Methylophilus_methylotrophus Methylophilus methylotrophus] with HEC as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | 1E8E is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Methylophilus_methylotrophus Methylophilus methylotrophus] with <scene name='pdbligand=HEC:'>HEC</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1E8E OCA]. | ||
==Reference== | ==Reference== | ||
| Line 16: | Line 16: | ||
[[Category: Fareleira, P.]] | [[Category: Fareleira, P.]] | ||
[[Category: Santos, H.]] | [[Category: Santos, H.]] | ||
[[Category: Turner, D | [[Category: Turner, D L.]] | ||
[[Category: HEC]] | [[Category: HEC]] | ||
[[Category: cytochrome c'']] | [[Category: cytochrome c'']] | ||
| Line 23: | Line 23: | ||
[[Category: redox-bohr effect]] | [[Category: redox-bohr effect]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:25:00 2008'' | ||
Revision as of 13:25, 21 February 2008
|
SOLUTION STRUCTURE OF METHYLOPHILUS METHYLOTROPHUS CYTOCHROME C. INSIGHTS INTO THE STRUCTURAL BASIS OF HAEM-LIGAND DETACHMENT
OverviewOverview
Cytochrome c" from Methylophilus methylotrophus is a monohaem protein with 124 amino acid residues. The iron has two histidine ligands in the oxidised form, one of which detaches and picks up a proton when the protein is reduced. Thus, both forms are paramagnetic. The structure of the oxidised form in solution, determined from NMR data is presented. The family of structures has an average backbone rmsd value of 0.53 A, and a heavy atom rmsd value of 0.95 A, within a target function range of 32 %. This structure is related to class I cytochromes with an additional helix at the N terminus. The haem-binding site occurs in a domain essentially lacking secondary structure motifs and the axial histidinyl residues were found in an unusual near perpendicular orientation. Moreover, a disulfide bridge is present, an uncommon structural feature among c-type cytochromes. The disulfide bridge, linking cysteine residues 96 and 104, forms a loop that confers rigidity and is essential to the detachment of the axial histidine (His95) as demonstrated by chemical disruption of the S-S bond. A route for protonation of the distal histidine involving haem propionate 17 is proposed and discussed in the light of available models for complex membrane proton pumps.
About this StructureAbout this Structure
1E8E is a Single protein structure of sequence from Methylophilus methylotrophus with as ligand. Full crystallographic information is available from OCA.
ReferenceReference
Solution structure of Methylophilus methylotrophus cytochrome c": insights into the structural basis of haem-ligand detachment., Brennan L, Turner DL, Fareleira P, Santos H, J Mol Biol. 2001 Apr 27;308(2):353-65. PMID:11327772
Page seeded by OCA on Thu Feb 21 12:25:00 2008