1JGI

Crystal Structure of the Active Site Mutant Glu328Gln of Amylosucrase from Neisseria polysaccharea in Complex with the Natural Substrate Sucrose


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.226 
  • R-Value Work: 0.186 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Crystal structures of amylosucrase from Neisseria polysaccharea in complex with D-glucose and the active site mutant Glu328Gln in complex with the natural substrate sucrose.

Mirza, O.Skov, L.K.Remaud-Simeon, M.Potocki de Montalk, G.Albenne, C.Monsan, P.Gajhede, M.

(2001) Biochemistry 40: 9032-9039

  • Primary Citation of Related Structures:  1JG9

  • PubMed Abstract: 
  • The structure of amylosucrase from Neisseria polysaccharea in complex with beta-D-glucose has been determined by X-ray crystallography at a resolution of 1.66 A. Additionally, the structure of the inactive active site mutant Glu328Gln in complex with ...

    The structure of amylosucrase from Neisseria polysaccharea in complex with beta-D-glucose has been determined by X-ray crystallography at a resolution of 1.66 A. Additionally, the structure of the inactive active site mutant Glu328Gln in complex with sucrose has been determined to a resolution of 2.0 A. The D-glucose complex shows two well-defined D-glucose molecules, one that binds very strongly in the bottom of a pocket that contains the proposed catalytic residues (at the subsite -1), in a nonstrained (4)C(1) conformation, and one that binds in the packing interface to a symmetry-related molecule. A third weaker D-glucose-binding site is located at the surface near the active site pocket entrance. The orientation of the D-glucose in the active site emphasizes the Glu328 role as the general acid/base. The binary sucrose complex shows one molecule bound in the active site, where the glucosyl moiety is located at the alpha-amylase -1 position and the fructosyl ring occupies subsite +1. Sucrose effectively blocks the only visible access channel to the active site. From analysis of the complex it appears that sucrose binding is primarily obtained through enzyme interactions with the glucosyl ring and that an important part of the enzyme function is a precise alignment of a lone pair of the linking O1 oxygen for hydrogen bond interaction with Glu328. The sucrose specificity appears to be determined primarily by residues Asp144, Asp394, Arg446, and Arg509. Both Asp394 and Arg446 are located in an insert connecting beta-strand 7 and alpha-helix 7 that is much longer in amylosucrase compared to other enzymes from the alpha-amylase family (family 13 of the glycoside hydrolases).


    Organizational Affiliation

    Protein Structure Group, Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
amylosucrase
A
628Neisseria polysacchareaGene Names: ams
EC: 2.4.1.4
Find proteins for Q9ZEU2 (Neisseria polysaccharea)
Go to UniProtKB:  Q9ZEU2
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SUC
Query on SUC

Download SDF File 
Download CCD File 
A
SUCROSE
C12 H22 O11
CZMRCDWAGMRECN-UGDNZRGBSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.226 
  • R-Value Work: 0.186 
  • Space Group: P 21 21 2
Unit Cell:
Length (Å)Angle (°)
a = 95.588α = 90.00
b = 116.739β = 90.00
c = 60.833γ = 90.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
CNSphasing
DENZOdata reduction
CNSrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2001-10-31
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance