2bc5
From Proteopedia
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| , resolution 2.25Å | |||||||
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| Ligands: | and | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
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. 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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