2bc5
Crystal structure of E. coli cytochrome b562 with engineered c-type heme linkagesCrystal structure of E. coli cytochrome b562 with engineered c-type heme linkages
Structural highlights
FunctionC562_ECOLX Electron-transport protein of unknown function. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe 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. 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[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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