1mqv
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| , resolution 1.78Å | |||||||
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| Ligands: | |||||||
| Related: | 1A7V
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| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Crystal Structure of the Q1A/F32W/W72F mutant of Rhodopseudomonas palustris cytochrome c' (prime) expressed in E. coli
OverviewOverview
We employed fluorescence energy-transfer probes to investigate the polypeptide dynamics accompanying cytochrome c' folding. Analysis of fluorescence energy-transfer kinetics from wild-type Trp-72 or Trp-32 in a crystallographically characterized (1.78 A) Q1A/F32W/W72F mutant shows that there is structural heterogeneity in denatured cytochrome c'. Even at guanidine hydrochloride concentrations well beyond the unfolding transition, a substantial fraction of the polypeptides ( approximately 50%) adopts compact conformations (tryptophan-to-heme distance, approximately 25 A) in both pseudo-wild-type (Q1A) and mutant proteins. A burst phase (< or =5 ms) is revealed when stopped flow-triggered refolding is probed by tryptophan intensity: measurements on the Q1A protein show that approximately 75% of the Trp-72 fluorescence (83% for Trp-32) is quenched within the mixing deadtime, suggesting that most of the polypeptides have collapsed.
About this StructureAbout this Structure
1MQV is a Single protein structure of sequence from Rhodopseudomonas palustris. Full crystallographic information is available from OCA.
ReferenceReference
Structural features of cytochrome c' folding intermediates revealed by fluorescence energy-transfer kinetics., Lee JC, Engman KC, Tezcan FA, Gray HB, Winkler JR, Proc Natl Acad Sci U S A. 2002 Nov 12;99(23):14778-82. Epub 2002 Oct 29. PMID:12407175
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