1SIF

Crystal structure of a multiple hydrophobic core mutant of ubiquitin


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.18 Å
  • R-Value Free: 0.248 
  • R-Value Work: 0.193 
  • R-Value Observed: 0.196 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Exploring sequence/folding space: folding studies on multiple hydrophobic core mutants of ubiquitin

Benitez-Cardoza, C.G.Stott, K.Hirshberg, M.Went, H.M.Woolfson, D.N.Jackson, S.E.

(2004) Biochemistry 43: 5195-5203

  • DOI: 10.1021/bi0361620
  • Primary Citation of Related Structures:  
    1SIF

  • PubMed Abstract: 
  • The stability, dynamic, and structural properties of ubiquitin and two multiple hydrophobic core mutants were studied. One of the mutants (U4) has seven substitutions in the hydrophobic core (M1L, I3L, V5I, I13F, L15V, V17M, and V26L). On average, it ...

    The stability, dynamic, and structural properties of ubiquitin and two multiple hydrophobic core mutants were studied. One of the mutants (U4) has seven substitutions in the hydrophobic core (M1L, I3L, V5I, I13F, L15V, V17M, and V26L). On average, its side chains are larger than the wild-type, and it can thus be thought of as having an overpacked core. The other mutant (U7) has two substitutions (I3V and I13V). On average, it has smaller side chains than the wild-type, and it can therefore be considered to be underpacked. The three proteins are well-folded and show similar backbone dynamics (T(1), T(2), and HNOE values), indicating that the regular secondary structure extends over the same residue ranges. The crystallographic structure of U4 was determined. The final R(factor) and R(free) are 0.198 and 0.248, respectively, at 2.18 A resolution. The structure of U4 is very similar to wild-type ubiquitin. Remarkably, there are almost no changes in the positions of the C(alpha) atoms along the entire backbone, and the hydrogen-bonding network is maintained. The mutations of the hydrophobic core are accommodated by small movements of side chains in the core of mutated and nonmutated residues. Unfolding and refolding kinetic studies revealed that U4 unfolds with the highest rates; however, its refolding rate constants are very similar to those of the wild-type protein. Conversely, U7 seems to be the most destabilized protein; its refolding rate constant is smaller than the other two proteins. This was confirmed by stopped-flow techniques and by H/D exchange methodologies. This work illustrates the possibility of repacking the hydrophobic core of small proteins and has important implications in the de novo design of stable proteins.


    Organizational Affiliation

    University of Cambridge, Chemistry Department, Lensfield Road, Cambridge, CB2 1EW, United Kingdom.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
ubiquitinA88Homo sapiensMutation(s): 7 
Gene Names: UBC
Find proteins for P0CG48 (Homo sapiens)
Explore P0CG48 
Go to UniProtKB:  P0CG48
NIH Common Fund Data Resources
PHAROS  P0CG48
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.18 Å
  • R-Value Free: 0.248 
  • R-Value Work: 0.193 
  • R-Value Observed: 0.196 
  • Space Group: I 2 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 46.806α = 90
b = 49.022β = 90
c = 75.856γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
MOSFLMdata reduction
CCP4data scaling
AMoREphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2004-07-27
    Type: Initial release
  • Version 1.1: 2008-04-29
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Advisory, Version format compliance