2HXX

Aminotryptophan Barstar


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.290 
  • R-Value Work: 0.251 

wwPDB Validation 3D Report Full Report


This is version 1.4 of the entry. See complete history

Literature

Aminotryptophan-containing barstar

Rubini, M.Lepthien, S.Golbik, R.Budisa, N.

(2006) BIOCHIM.BIOPHYS.ACTA 1764: 1147-1158

  • DOI: 10.1016/j.bbapap.2006.04.012

  • PubMed Abstract: 
  • The indole ring of the canonical amino acid tryptophan (Trp) possesses distinguished features, such as sterical bulk, hydrophobicity and the nitrogen atom which is capable of acting as a hydrogen bond donor. The introduction of an amino group into th ...

    The indole ring of the canonical amino acid tryptophan (Trp) possesses distinguished features, such as sterical bulk, hydrophobicity and the nitrogen atom which is capable of acting as a hydrogen bond donor. The introduction of an amino group into the indole moiety of Trp yields the structural analogs 4-aminotryptophan ((4-NH(2))Trp) and 5-aminotryptophan ((5-NH(2))Trp). Their hydrophobicity and spectral properties are substantially different when compared to those of Trp. They resemble the purine bases of DNA and share their capacity for pH-sensitive intramolecular charge transfer. The Trp --> aminotryptophan substitution in proteins during ribosomal translation is expected to result in related protein variants that acquire these features. These expectations have been fulfilled by incorporating (4-NH(2))Trp and (5-NH(2))Trp into barstar, an intracellular inhibitor of the ribonuclease barnase from Bacillus amyloliquefaciens. The crystal structure of (4-NH(2))Trp-barstar is similar to that of the parent protein, whereas its spectral and thermodynamic behavior is found to be remarkably different. The T(m) value of (4-NH(2))Trp- and (5-NH(2))Trp-barstar is lowered by about 20 degrees Celsius, and they exhibit a strongly reduced unfolding cooperativity and substantial loss of free energy in folding. Furthermore, folding kinetic study of (4-NH(2))Trp-barstar revealed that the denatured state is even preferred over native one. The combination of structural and thermodynamic analyses clearly shows how structures of substituted barstar display a typical structure-function tradeoff: the acquirement of unique pH-sensitive charge transfer as a novel function is achieved at the expense of protein stability. These findings provide a new insight into the evolution of the amino acid repertoire of the universal genetic code and highlight possible problems regarding protein engineering and design by using an expanded genetic code.


    Organizational Affiliation

    Max-Planck-Institut für Biochemie, Am Klopferspitz 18, D-82152 Martinsried, Germany.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Barstar
A, B
89Bacillus amyloliquefaciensMutation(s): 3 
Find proteins for P11540 (Bacillus amyloliquefaciens)
Go to UniProtKB:  P11540
Small Molecules
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
4IN
Query on 4IN
A, B
L-PEPTIDE LINKINGC11 H13 N3 O2TRP
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.290 
  • R-Value Work: 0.251 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 85.160α = 90.00
b = 46.850β = 121.34
c = 51.060γ = 90.00
Software Package:
Software NamePurpose
AMoREphasing
MAR345data collection
CNSrefinement
MOSFLMdata reduction
CCP4data scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2006-08-22
    Type: Initial release
  • Version 1.1: 2008-05-01
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2012-02-08
    Type: Structure summary
  • Version 1.4: 2017-10-18
    Type: Advisory, Refinement description