1NH6

Structure of S. marcescens chitinase A, E315L, complex with hexasaccharide


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.05 Å
  • R-Value Free: 0.227 
  • R-Value Work: 0.197 
  • R-Value Observed: 0.197 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report


This is version 2.2 of the entry. See complete history


Literature

Family 18 chitinase-oligosaccharide substrate interaction: subsite preference and anomer selectivity of Serratia marcescens chitinase A.

Aronson Jr., N.N.Halloran, B.A.Alexyev, M.F.Amable, L.Madura, J.D.Pasupulati, L.Worth, C.Van Roey, P.

(2003) Biochem J 376: 87-95

  • DOI: https://doi.org/10.1042/BJ20030273
  • Primary Citation of Related Structures:  
    1NH6

  • PubMed Abstract: 

    The sizes and anomers of the products formed during the hydrolysis of chitin oligosaccharides by the Family 18 chitinase A (ChiA) from Serratia marcescens were analysed by hydrophilic interaction chromatography using a novel approach in which reactions were performed at 0 degrees C to stabilize the anomer conformations of the initial products. Crystallographic studies of the enzyme, having the structure of the complex of the ChiA E315L (Glu315-->Leu) mutant with a hexasaccharide, show that the oligosaccharide occupies subsites -4 to +2 in the substrate-binding cleft, consistent with the processing of beta-chitin by the release of disaccharide at the reducing end. Products of the hydrolysis of hexa- and penta-saccharides by wild-type ChiA, as well as by two mutants of the residues Trp275 and Phe396 important in binding the substrate at the +1 and +2 sites, show that the substrates only occupy sites -2 to +2 and that additional N -acetyl-D-glucosamines extend beyond the substrate-binding cleft at the reducing end. The subsites -3 and -4 are not used in this four-site binding mode. The explanation for these results is found in the high importance of individual binding sites for the processing of short oligosaccharides compared with the cumulative recognition and processive hydrolysis mechanism used to digest natural beta-chitin.


  • Organizational Affiliation

    Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, AL 36688, USA. naronson@jaguar1.usouthal.edu


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
chitinase A540Serratia marcescensMutation(s): 1 
EC: 3.2.1.14
Membrane Entity: Yes 
UniProt
Find proteins for P07254 (Serratia marcescens)
Explore P07254 
Go to UniProtKB:  P07254
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP07254
Sequence Annotations
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  • Reference Sequence
Oligosaccharides

Help

Entity ID: 2
MoleculeChains Length2D Diagram Glycosylation3D Interactions
2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose
B
6N/A
Glycosylation Resources
GlyTouCan:  G36414FS
GlyCosmos:  G36414FS
GlyGen:  G36414FS
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.05 Å
  • R-Value Free: 0.227 
  • R-Value Work: 0.197 
  • R-Value Observed: 0.197 
  • Space Group: I 2 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 78.1α = 90
b = 135.23β = 90
c = 188.07γ = 90
Software Package:
Software NamePurpose
CNSrefinement
MOSFLMdata reduction
CCP4data scaling
AMoREphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2003-03-18
    Type: Initial release
  • Version 1.1: 2008-04-29
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Non-polymer description, Version format compliance
  • Version 2.0: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Atomic model, Data collection, Derived calculations, Structure summary
  • Version 2.1: 2021-10-27
    Changes: Database references, Structure summary
  • Version 2.2: 2023-08-16
    Changes: Data collection, Refinement description