3HPI

Crystal structure of maltose-binding protein mutant with bound sucrose


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.284 
  • R-Value Work: 0.228 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Studies of the maltose transport system reveal a mechanism for coupling ATP hydrolysis to substrate translocation without direct recognition of substrate.

Gould, A.D.Shilton, B.H.

(2010) J.Biol.Chem. 285: 11290-11296

  • DOI: 10.1074/jbc.M109.089078
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • The ATPase activity of the maltose transporter (MalFGK(2)) is dependent on interactions with the maltose-binding protein (MBP). To determine whether direct interactions between the translocated sugar and MalFGK(2) are important for the regulation of ...

    The ATPase activity of the maltose transporter (MalFGK(2)) is dependent on interactions with the maltose-binding protein (MBP). To determine whether direct interactions between the translocated sugar and MalFGK(2) are important for the regulation of ATP hydrolysis, we used an MBP mutant (sMBP) that is able to bind either maltose or sucrose. We observed that maltose- and sucrose-bound sMBP stimulate equal levels of MalFGK(2) ATPase activity. Therefore, the ATPase activity of MalFGK(2) is coupled to translocation of maltose solely by interactions between MalFGK(2) and MBP. For both maltose and sucrose, the ability of sMBP to stimulate the MalFGK(2) ATPase was greatly reduced compared with wild-type MBP, indicating that the mutations in sMBP have interfered with important interactions between MBP and MalFGK(2). High resolution crystal structure analysis of sMBP shows that in the closed conformation with bound sucrose, three of four mutations are buried, and the fourth causes only a minor change in the accessible surface. In contrast, in the open form of sMBP, all of the mutations are accessible, and the main chain of Tyr(62)-Gly(69) is destabilized and occupies an alternative conformation due to the W62Y mutation. On this basis, the compromised ability of sMBP to stimulate ATP hydrolysis by MalFGK(2) is most likely due to a disruption of interactions between MalFGK(2) and the open, rather than the closed, conformation of sMBP. Modeling the open sMBP structure bound to MalFGK(2) in the transition state for ATP hydrolysis points to an important site of interaction and suggests a mechanism for coupling ATP hydrolysis to substrate translocation that is independent of the exact structure of the substrate.


    Related Citations: 
    • Directed evolution of protein switches and their application to the creation of ligand-binding proteins.
      Guntas, G.,Mansell, T.J.,Kim, J.R.,Ostermeier, M.
      (2005) Proc.Natl.Acad.Sci.USA 102: 11224


    Organizational Affiliation

    Department of Biochemistry, University of Western Ontario, London, Ontario N6B 2G3, Canada.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Maltose-binding periplasmic protein
A, B
372Escherichia coli (strain K12)Mutation(s): 4 
Gene Names: malE
Find proteins for P0AEX9 (Escherichia coli (strain K12))
Go to UniProtKB:  P0AEX9
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SUC
Query on SUC

Download SDF File 
Download CCD File 
A, B
SUCROSE
C12 H22 O11
CZMRCDWAGMRECN-UGDNZRGBSA-N
 Ligand Interaction
ZN
Query on ZN

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Download CCD File 
A, B
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
ACT
Query on ACT

Download SDF File 
Download CCD File 
A, B
ACETATE ION
C2 H3 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-M
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
SUCKd: 6600 nM BINDINGMOAD
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.284 
  • R-Value Work: 0.228 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 60.042α = 90.00
b = 85.229β = 90.00
c = 132.864γ = 90.00
Software Package:
Software NamePurpose
CNSrefinement
SCALEPACKdata scaling
MOLREPphasing
HKL-2000data reduction
DENZOdata reduction
HKL-2000data collection
PDB_EXTRACTdata extraction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2010-02-09
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Source and taxonomy, Version format compliance
  • Version 1.2: 2017-11-01
    Type: Refinement description