1rcp
From Proteopedia
(New page: 200px<br /><applet load="1rcp" size="450" color="white" frame="true" align="right" spinBox="true" caption="1rcp, resolution 2.Å" /> '''CYTOCHROME C''''<br />...) |
|||
| Line 1: | Line 1: | ||
| - | [[Image:1rcp.jpg|left|200px]]<br /><applet load="1rcp" size=" | + | [[Image:1rcp.jpg|left|200px]]<br /><applet load="1rcp" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1rcp, resolution 2.Å" /> | caption="1rcp, resolution 2.Å" /> | ||
'''CYTOCHROME C''''<br /> | '''CYTOCHROME C''''<br /> | ||
==Overview== | ==Overview== | ||
| - | The structures of two polymorphs of cytochrome c' from Rhodobacter | + | The structures of two polymorphs of cytochrome c' from Rhodobacter capsulatus (RCCP) strain M110 have been determined by the molecular replacement method. Iron anomalous scattering data were used to confirm the molecular replacement solution. The structures were refined at 1.72 angstrom and 2.0 angstrom resolution to R-values of 15.0% and 16.3%, respectively. The RCCP molecule is a dimer and each of the identical 129 residue subunits folds as a four-helical bundle with a covalently bound heme group in the center. This structural motif resembles that of cytochromes c' reported from Rhodospirillum molischianum (RMCP), Rhodospirillum rubrum (RRCP), Chromatium vinosum (CVCP), Achromobacter xyloseoxidans (AXCP) and Alcaligenes denitrificans (ADCP). However, the architecture of the RCCP dimer, that is, the mode of association of subunits, differs substantially from that of the other cytochromes c'. In the RCCP dimer, the subunits are roughly parallel with each other and only helix B of each subunit participates in formation of the dimer interface. Measurement of the solvent-accessible surface area indicates that the dimer interface is smaller in RCCP than in the other cytochromes c'. In RMCP, CVCP, RRCP, AXCP and ADCP the subunits cross each other to form an X shape, and two helices, A and B, of each subunit interact across the dimer interface. These results are consistent with hydrodynamic measurements, which show that there is an equilibrium between monomers and dimer in RCCP, whereas the dimer is the predominant form in the other cytochromes c' for which structures have been determined. Structural comparison of the six cytochromes c' reveal that they can be divided into two groups. In group 1 cytochromes c', CVCP and RCCP, the amino acid sequences and the folding of subunits are arranged in such a way as to allow the formation of a deep channel between helices B and C with direct solvent accessibility to the heme sixth ligand position. There is no such channel in group 2 cytochromes c', RMCP, RRCP, AXCP and ADCP. This may account, in part, for the differences in carbon monoxide binding. |
==About this Structure== | ==About this Structure== | ||
| - | 1RCP is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Rhodobacter_capsulatus Rhodobacter capsulatus] with HEM as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1RCP is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Rhodobacter_capsulatus Rhodobacter capsulatus] with <scene name='pdbligand=HEM:'>HEM</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1RCP OCA]. |
==Reference== | ==Reference== | ||
| Line 13: | Line 13: | ||
[[Category: Rhodobacter capsulatus]] | [[Category: Rhodobacter capsulatus]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Cusanovich, M | + | [[Category: Cusanovich, M A.]] |
[[Category: Higuchi, Y.]] | [[Category: Higuchi, Y.]] | ||
| - | [[Category: Meyer, T | + | [[Category: Meyer, T E.]] |
[[Category: Misaki, S.]] | [[Category: Misaki, S.]] | ||
| - | [[Category: Tahirov, T | + | [[Category: Tahirov, T H.]] |
[[Category: Yasuoka, N.]] | [[Category: Yasuoka, N.]] | ||
[[Category: HEM]] | [[Category: HEM]] | ||
| Line 24: | Line 24: | ||
[[Category: heme]] | [[Category: heme]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:49:32 2008'' |
Revision as of 12:49, 21 February 2008
|
CYTOCHROME C'
Overview
The structures of two polymorphs of cytochrome c' from Rhodobacter capsulatus (RCCP) strain M110 have been determined by the molecular replacement method. Iron anomalous scattering data were used to confirm the molecular replacement solution. The structures were refined at 1.72 angstrom and 2.0 angstrom resolution to R-values of 15.0% and 16.3%, respectively. The RCCP molecule is a dimer and each of the identical 129 residue subunits folds as a four-helical bundle with a covalently bound heme group in the center. This structural motif resembles that of cytochromes c' reported from Rhodospirillum molischianum (RMCP), Rhodospirillum rubrum (RRCP), Chromatium vinosum (CVCP), Achromobacter xyloseoxidans (AXCP) and Alcaligenes denitrificans (ADCP). However, the architecture of the RCCP dimer, that is, the mode of association of subunits, differs substantially from that of the other cytochromes c'. In the RCCP dimer, the subunits are roughly parallel with each other and only helix B of each subunit participates in formation of the dimer interface. Measurement of the solvent-accessible surface area indicates that the dimer interface is smaller in RCCP than in the other cytochromes c'. In RMCP, CVCP, RRCP, AXCP and ADCP the subunits cross each other to form an X shape, and two helices, A and B, of each subunit interact across the dimer interface. These results are consistent with hydrodynamic measurements, which show that there is an equilibrium between monomers and dimer in RCCP, whereas the dimer is the predominant form in the other cytochromes c' for which structures have been determined. Structural comparison of the six cytochromes c' reveal that they can be divided into two groups. In group 1 cytochromes c', CVCP and RCCP, the amino acid sequences and the folding of subunits are arranged in such a way as to allow the formation of a deep channel between helices B and C with direct solvent accessibility to the heme sixth ligand position. There is no such channel in group 2 cytochromes c', RMCP, RRCP, AXCP and ADCP. This may account, in part, for the differences in carbon monoxide binding.
About this Structure
1RCP is a Single protein structure of sequence from Rhodobacter capsulatus with as ligand. Full crystallographic information is available from OCA.
Reference
High-resolution crystal structures of two polymorphs of cytochrome c' from the purple phototrophic bacterium rhodobacter capsulatus., Tahirov TH, Misaki S, Meyer TE, Cusanovich MA, Higuchi Y, Yasuoka N, J Mol Biol. 1996 Jun 14;259(3):467-79. PMID:8676382
Page seeded by OCA on Thu Feb 21 14:49:32 2008
