3WD3

Serratia marcescens Chitinase B complexed with azide inhibitor

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.20 Å
  • R-Value Free: 0.198 
  • R-Value Work: 0.169 
  • R-Value Observed: 0.171 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history. 


Literature

Observation of the controlled assembly of preclick components in the in situ click chemistry generation of a chitinase inhibitor

Hirose, T., Maita, N., Gouda, H., Koseki, J., Yamamoto, T., Sugawara, A., Nakano, H., Hirono, S., Shiomi, K., Watanabe, T., Taniguchi, H., Sharpless, K.B., Omura, S., Sunazuka, T.

(2013) Proc Natl Acad Sci U S A 110: 15892-15897

  • DOI: 10.1073/pnas.1315049110
  • Primary Citation of Related Structures:  
    3WD0, 3WD1, 3WD2, 3WD3, 3WD4

  • PubMed Abstract: 

    • The Huisgen cycloaddition of azides and alkynes, accelerated by target biomolecules, termed "in situ click chemistry," has been successfully exploited to discover highly potent enzyme inhibitors. We have previously reported a specific Serratia marcescens chitinase B (SmChiB)-templated syn-triazole inhibitor generated in situ from an azide-bearing inhibitor and an alkyne fragment ...

    The Huisgen cycloaddition of azides and alkynes, accelerated by target biomolecules, termed "in situ click chemistry," has been successfully exploited to discover highly potent enzyme inhibitors. We have previously reported a specific Serratia marcescens chitinase B (SmChiB)-templated syn-triazole inhibitor generated in situ from an azide-bearing inhibitor and an alkyne fragment. Several in situ click chemistry studies have been reported. Although some mechanistic evidence has been obtained, such as X-ray analysis of [protein]-["click ligand"] complexes, indicating that proteins act as both mold and template between unique pairs of azide and alkyne fragments, to date, observations have been based solely on "postclick" structural information. Here, we describe crystal structures of SmChiB complexed with an azide ligand and an O-allyl oxime fragment as a mimic of a click partner, revealing a mechanism for accelerating syn-triazole formation, which allows generation of its own distinct inhibitor. We have also performed density functional theory calculations based on the X-ray structure to explore the acceleration of the Huisgen cycloaddition by SmChiB. The density functional theory calculations reasonably support that SmChiB plays a role by the cage effect during the pretranslation and posttranslation states of selective syn-triazole click formation.

    Organizational Affiliation: 

    The Kitasato Institute, Kitasato Institute for Life Sciences and Graduate School of Infection Control Sciences, and School of Pharmacy, Kitasato University, Tokyo 108-8641, Japan.



Macromolecules
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(by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Chitinase B A503Serratia marcescensMutation(s): 0 
Gene Names: chiB
EC: 3.2.1.14
Find proteins for P11797 (Serratia marcescens)
Explore P11797 
Go to UniProtKB:  P11797
Protein Feature View
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  • Reference Sequence
Small Molecules
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
A1LIC50:  580   nM  Binding MOAD
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.20 Å
  • R-Value Free: 0.198 
  • R-Value Work: 0.169 
  • R-Value Observed: 0.171 
  • Space Group: P 43 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 97.688α = 90
b = 97.688β = 90
c = 197.434γ = 90
Software Package:
Software NamePurpose
ADSCdata collection
MOLREPphasing
REFMACrefinement
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

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View more in-depth experimental data

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2013-09-18
    Type: Initial release
  • Version 1.1: 2013-11-06
    Changes: Database references