2bc5
From Proteopedia
(New page: 200px<br /><applet load="2bc5" size="450" color="white" frame="true" align="right" spinBox="true" caption="2bc5, resolution 2.25Å" /> '''Crystal structure of...) |
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| - | [[Image:2bc5.gif|left|200px]]<br /><applet load="2bc5" size=" | + | [[Image:2bc5.gif|left|200px]]<br /><applet load="2bc5" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="2bc5, resolution 2.25Å" /> | caption="2bc5, resolution 2.25Å" /> | ||
'''Crystal structure of E. coli cytochrome b562 with engineered c-type heme linkages'''<br /> | '''Crystal structure of E. coli cytochrome b562 with engineered c-type heme linkages'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The four-helix-bundle protein fold can be constructed from a wide variety | + | The four-helix-bundle protein fold can be constructed from a wide variety of primary amino acid sequences. Proteins with this structure are excellent candidates for investigations of the relationship between folding mechanism and topology. The folding of cytochrome b(562), a four-helix-bundle heme protein, is hampered by heme dissociation. To overcome this complication, we have engineered a variant of cytochrome b(562) (cyt c-b(562)) featuring a c-type linkage between the heme and the polypeptide chain. The replacement of the native cyt b(562) leader sequence in this protein with that of a c-type cytochrome (cyt c(556)) led to high yields of fully matured and correctly folded cyt c-b(562). We have determined the X-ray crystal structure of cyt c-b(562) at 2.25 A and characterized its physical, chemical, and folding properties. These measurements reveal that the c-type linkage does not perturb the protein fold or reduction potential of the heme group. The covalent attachment of the porphyrin to the polypeptide does, however, produce a substantial change in protein stability and folding kinetics. |
==About this Structure== | ==About this Structure== | ||
| - | 2BC5 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with SO4 and HEM as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 2BC5 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=SO4:'>SO4</scene> and <scene name='pdbligand=HEM:'>HEM</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2BC5 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Faraone-Mennella, J.]] | [[Category: Faraone-Mennella, J.]] | ||
| - | [[Category: Gray, H | + | [[Category: Gray, H B.]] |
| - | [[Category: Tezcan, F | + | [[Category: Tezcan, F A.]] |
| - | [[Category: Winkler, J | + | [[Category: Winkler, J R.]] |
[[Category: HEM]] | [[Category: HEM]] | ||
[[Category: SO4]] | [[Category: SO4]] | ||
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[[Category: r98c and y101c mutations]] | [[Category: r98c and y101c mutations]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:36:13 2008'' |
Revision as of 14:36, 21 February 2008
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Crystal structure of E. coli cytochrome b562 with engineered c-type heme linkages
Overview
The four-helix-bundle protein fold can be constructed from a wide variety of primary amino acid sequences. Proteins with this structure are excellent candidates for investigations of the relationship between folding mechanism and topology. The folding of cytochrome b(562), a four-helix-bundle heme protein, is hampered by heme dissociation. To overcome this complication, we have engineered a variant of cytochrome b(562) (cyt c-b(562)) featuring a c-type linkage between the heme and the polypeptide chain. The replacement of the native cyt b(562) leader sequence in this protein with that of a c-type cytochrome (cyt c(556)) led to high yields of fully matured and correctly folded cyt c-b(562). We have determined the X-ray crystal structure of cyt c-b(562) at 2.25 A and characterized its physical, chemical, and folding properties. These measurements reveal that the c-type linkage does not perturb the protein fold or reduction potential of the heme group. The covalent attachment of the porphyrin to the polypeptide does, however, produce a substantial change in protein stability and folding kinetics.
About this Structure
2BC5 is a Single protein structure of sequence from Escherichia coli with and as ligands. Full crystallographic information is available from OCA.
Reference
Stability and folding kinetics of structurally characterized cytochrome c-b562., Faraone-Mennella J, Tezcan FA, Gray HB, Winkler JR, Biochemistry. 2006 Sep 5;45(35):10504-11. PMID:16939202
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