4IHE

Crystal Structure of Uncleaved ThnT T282A

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.50 Å
  • R-Value Free: 0.180 
  • R-Value Work: 0.165 
  • R-Value Observed: 0.166 

wwPDB Validation   3D Report Full Report


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Literature

Exploring the Role of Conformational Heterogeneity in cis-Autoproteolytic Activation of ThnT.

Buller, A.R., Freeman, M.F., Schildbach, J.F., Townsend, C.A.

(2014) Biochemistry 53: 4273-4281

  • DOI: 10.1021/bi500385d
  • Primary Citation of Related Structures:  
    4IHD, 4IHE

  • PubMed Abstract: 

    • In the past decade, there have been major achievements in understanding the relationship between enzyme catalysis and protein structural plasticity. In autoprocessing systems, however, there is a sparsity of direct evidence of the role of conformational dynamics, which are complicated by their intrinsic chemical reactivity ...

    In the past decade, there have been major achievements in understanding the relationship between enzyme catalysis and protein structural plasticity. In autoprocessing systems, however, there is a sparsity of direct evidence of the role of conformational dynamics, which are complicated by their intrinsic chemical reactivity. ThnT is an autoproteolytically activated enzyme involved in the biosynthesis of the β-lactam antibiotic thienamycin. Conservative mutation of ThnT results in multiple conformational states that can be observed via X-ray crystallography, establishing ThnT as a representative and revealing system for studing how conformational dynamics control autoactivation at a molecular level. Removal of the nucleophile by mutation to Ala disrupts the population of a reactive state and causes widespread structural changes from a conformation that promotes autoproteolysis to one associated with substrate catalysis. Finer probing of the active site polysterism was achieved by EtHg derivatization of the nucleophile, which indicates the active site and a neighboring loop have coupled dynamics. Disruption of these interactions by mutagenesis precludes the ability to observe a reactive state through X-ray crystallography, and application of this insight to other autoproteolytically activated enzymes offers an explanation for the widespread crystallization of inactive states. We suggest that the N→O(S) acyl shift in cis-autoproteolysis might occur through a si-face attack, thereby unifying the fundamental chemistry of these enzymes through a common mechanism.

    Organizational Affiliation: 

    Department of Biophysics, Johns Hopkins University , Baltimore, Maryland 21218, United States.



Macromolecules
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Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
ThnT proteinA, B419Streptomyces cattleyaMutation(s): 1 
Gene Names: ThnT
EC: 3.5.1.92
UniProt
Find proteins for Q83XN4 (Streptomyces cattleya)
Explore Q83XN4 
Go to UniProtKB:  Q83XN4
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ83XN4
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.50 Å
  • R-Value Free: 0.180 
  • R-Value Work: 0.165 
  • R-Value Observed: 0.166 
  • Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 140.754α = 90
b = 67.959β = 90
c = 73.507γ = 90
Software Package:
Software NamePurpose
HKL-2000data collection
PHASERphasing
REFMACrefinement
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2014-08-13
    Type: Initial release