2GH9

Thermus thermophilus maltotriose binding protein bound with maltotriose


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.254 
  • R-Value Work: 0.197 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Structural adaptations that modulate monosaccharide, disaccharide, and trisaccharide specificities in periplasmic maltose-binding proteins.

Cuneo, M.J.Changela, A.Beese, L.S.Hellinga, H.W.

(2009) J.Mol.Biol. 389: 157-166

  • DOI: 10.1016/j.jmb.2009.04.008

  • PubMed Abstract: 
  • Periplasmic binding proteins comprise a superfamily that is present in archaea, prokaryotes, and eukaryotes. Periplasmic binding protein ligand-binding sites have diversified to bind a wide variety of ligands. Characterization of the structural mecha ...

    Periplasmic binding proteins comprise a superfamily that is present in archaea, prokaryotes, and eukaryotes. Periplasmic binding protein ligand-binding sites have diversified to bind a wide variety of ligands. Characterization of the structural mechanisms by which functional adaptation occurs is key to understanding the evolution of this important protein superfamily. Here we present the structure and ligand-binding properties of a maltotriose-binding protein identified from the Thermus thermophilus genome sequence. We found that this receptor has a high affinity for the trisaccharide maltotriose (K(d)<1 microM) but little affinity for disaccharides that are transported by a paralogous maltose transport operon present in T. thermophilus. Comparison of this structure to other proteins that adopt the maltose-binding protein fold but bind monosaccharides, disaccharides, or trisaccharides reveals the presence of four subsites that bind individual glucose ring units. Two loops and three helical segments encode adaptations that control the presence of each subsite by steric blocking or hydrogen bonding. We provide a model in which the energetics of long-range conformational equilibria controls subsite occupancy and ligand binding.


    Organizational Affiliation

    Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
maltose/maltodextrin-binding protein
A
386Thermus thermophilus (strain HB27 / ATCC BAA-163 / DSM 7039)Mutation(s): 0 
Find proteins for Q72I44 (Thermus thermophilus (strain HB27 / ATCC BAA-163 / DSM 7039))
Go to UniProtKB:  Q72I44
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
MLR
Query on MLR

Download SDF File 
Download CCD File 
A
MALTOTRIOSE
AMYLOTRIOSE
C18 H32 O16
FYGDTMLNYKFZSV-PXXRMHSHSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
MLRKd: 1000 nM BINDINGMOAD
MLRKd: 1000 nM PDBBIND
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.254 
  • R-Value Work: 0.197 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 58.090α = 90.00
b = 68.994β = 90.00
c = 90.085γ = 90.00
Software Package:
Software NamePurpose
AMoREphasing
REFMACrefinement
MAR345data collection
SCALEPACKdata scaling
DENZOdata reduction
PDB_EXTRACTdata extraction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-02-06
    Type: Initial release
  • Version 1.1: 2008-05-01
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Source and taxonomy, Version format compliance
  • Version 1.3: 2017-10-18
    Type: Refinement description