2o79: Difference between revisions
No edit summary |
No edit summary |
||
| Line 1: | Line 1: | ||
[[Image:2o79.gif|left|200px]] | [[Image:2o79.gif|left|200px]] | ||
<!-- | |||
The line below this paragraph, containing "STRUCTURE_2o79", creates the "Structure Box" on the page. | |||
You may change the PDB parameter (which sets the PDB file loaded into the applet) | |||
or the SCENE parameter (which sets the initial scene displayed when the page is loaded), | |||
or leave the SCENE parameter empty for the default display. | |||
| | --> | ||
| | {{STRUCTURE_2o79| PDB=2o79 | SCENE= }} | ||
}} | |||
'''T4 lysozyme with C-terminal extension''' | '''T4 lysozyme with C-terminal extension''' | ||
| Line 31: | Line 28: | ||
[[Category: Llinas, M.]] | [[Category: Llinas, M.]] | ||
[[Category: Marqusee, S.]] | [[Category: Marqusee, S.]] | ||
[[Category: | [[Category: Circular permutant]] | ||
[[Category: | [[Category: Lysozyme]] | ||
[[Category: | [[Category: Protein folding]] | ||
[[Category: | [[Category: Protein stability]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun May 4 10:24:30 2008'' | |||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | |||
Revision as of 10:24, 4 May 2008
T4 lysozyme with C-terminal extension
OverviewOverview
Small proteins are generally observed to fold in an apparent two-state manner. Recently, however, more sensitive techniques have demonstrated that even seemingly single-domain proteins are actually made up of smaller subdomains. T4 lysozyme is one such protein. We explored the relative autonomy of its two individual subdomains and their contribution to the overall stability of T4 lysozyme by examining a circular permutation (CP13*) that relocates the N-terminal A-helix, creating subdomains that are contiguous in sequence. By determining the high-resolution structure of CP13* and characterizing its energy landscape using native state hydrogen exchange (NSHX), we show that connectivity between the subdomains is an important determinant of the energetic cooperativity but not structural integrity of the protein. The circular permutation results in a protein more easily able to populate a partially unfolded form in which the C-terminal subdomain is folded and the N-terminal subdomain is unfolded. We also created a fragment model of this intermediate and demonstrate using X-ray crystallography that its structure is identical to the corresponding residues in the full-length protein with the exception of a small network of hydrophobic interactions. In sum, we conclude that the C-terminal subdomain dominates the energetics of T4 lysozyme folding, and the A-helix serves an important role in coupling the two subdomains.
About this StructureAbout this Structure
2O79 is a Single protein structure of sequence from Enterobacteria phage t4. Full crystallographic information is available from OCA.
ReferenceReference
Exploring subdomain cooperativity in T4 lysozyme I: structural and energetic studies of a circular permutant and protein fragment., Cellitti J, Llinas M, Echols N, Shank EA, Gillespie B, Kwon E, Crowder SM, Dahlquist FW, Alber T, Marqusee S, Protein Sci. 2007 May;16(5):842-51. Epub 2007 Mar 30. PMID:17400926 Page seeded by OCA on Sun May 4 10:24:30 2008