1mqv: Difference between revisions
New page: left|200px<br /><applet load="1mqv" size="450" color="white" frame="true" align="right" spinBox="true" caption="1mqv, resolution 1.78Å" /> '''Crystal Structure of... |
No edit summary |
||
| Line 1: | Line 1: | ||
[[Image:1mqv.gif|left|200px]]<br /><applet load="1mqv" size=" | [[Image:1mqv.gif|left|200px]]<br /><applet load="1mqv" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="1mqv, resolution 1.78Å" /> | caption="1mqv, resolution 1.78Å" /> | ||
'''Crystal Structure of the Q1A/F32W/W72F mutant of Rhodopseudomonas palustris cytochrome c' (prime) expressed in E. coli'''<br /> | '''Crystal Structure of the Q1A/F32W/W72F mutant of Rhodopseudomonas palustris cytochrome c' (prime) expressed in E. coli'''<br /> | ||
==Overview== | ==Overview== | ||
We employed fluorescence energy-transfer probes to investigate the | 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 Structure== | ==About this Structure== | ||
1MQV is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Rhodopseudomonas_palustris Rhodopseudomonas palustris] with HEM as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | 1MQV is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Rhodopseudomonas_palustris Rhodopseudomonas palustris] 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=1MQV OCA]. | ||
==Reference== | ==Reference== | ||
| Line 13: | Line 13: | ||
[[Category: Rhodopseudomonas palustris]] | [[Category: Rhodopseudomonas palustris]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Engman, K | [[Category: Engman, K C.]] | ||
[[Category: Gray, H | [[Category: Gray, H B.]] | ||
[[Category: Lee, J | [[Category: Lee, J C.]] | ||
[[Category: Tezcan, F | [[Category: Tezcan, F A.]] | ||
[[Category: Winkler, J | [[Category: Winkler, J R.]] | ||
[[Category: HEM]] | [[Category: HEM]] | ||
[[Category: four-helix bundle]] | [[Category: four-helix bundle]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:58:06 2008'' | ||
Revision as of 11:58, 21 February 2008
|
Crystal Structure of the Q1A/F32W/W72F mutant of Rhodopseudomonas palustris cytochrome c' (prime) expressed in E. coli
Overview
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 Structure
1MQV is a Single protein structure of sequence from Rhodopseudomonas palustris with HEM as ligand. Full crystallographic information is available from OCA.
Reference
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
Page seeded by OCA on Thu Feb 21 13:58:06 2008
