Crystal structure of ABC transporter alpha-glycoside-binding mutant protein W287A in complex with maltose

Experimental Data Snapshot

  • Resolution: 1.63 Å
  • R-Value Free: 0.162 
  • R-Value Work: 0.137 
  • R-Value Observed: 0.138 

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Structural and thermodynamic correlation illuminates the selective transport mechanism of disaccharide alpha-glycosides through ABC transporter.

Chandravanshi, M.Gogoi, P.Kanaujia, S.P.

(2020) FEBS J 287: 1576-1597

  • DOI: https://doi.org/10.1111/febs.15093
  • Primary Citation of Related Structures:  
    6J9W, 6J9Y, 6JAD, 6JAG, 6JAH, 6JAI, 6JAL, 6JAM, 6JAN, 6JAO, 6JAP, 6JAQ, 6JAR, 6JAZ, 6JB0, 6JB4, 6JBA, 6JBB, 6JBE

  • PubMed Abstract: 

    Carbohydrate (or sugar) molecules are extremely diverse regarding their length, linkage and epimeric state. Selective acquisition of these molecules inside the cell is achieved by the substrate (or solute)-binding protein of ATP-binding cassette (ABC) transport system. However, the molecular mechanism underlying the selective transport of diverse carbohydrates remains unclear mainly owing to their structural complexity and stereochemistry. This study reports crystal structures of an α-glycoside-binding protein (αGlyBP, ORF ID: TTHA0356 from Thermus thermophilus HB8) in complex with disaccharide α-glycosides namely trehalose (α-1,1), sucrose (α-1,2), maltose (α-1,4), palatinose (α-1,6) and glucose within a resolution range of 1.6-2.0 Å. Despite transporting multiple types of sugars, αGlyBP maintains its stereoselectivity for both glycosidic linkage as well as an epimeric hydroxyl group. Out of the two subsites identified in the active-site pocket, subsite B which accommodates the glucose and glycosyl unit of disaccharide α-glycosides is highly conserved. In addition, structural data confirms the paradoxical behavior of glucose, where it replaces the high-affinity ligand(s) (disaccharide α-glycosides) from the active site of the protein. Comparative assessment of open and closed conformations of αGlyBP along with mutagenic and thermodynamic studies identifies the hinge region as the first interaction site for the ligands. On the other hand, encapsulation of ligand inside the active site is achieved through the N-terminal domain (NTD) movement, whereas the C-terminal domain (CTD) of αGlyBP is identified to be rigid and postulated to be responsible for maintaining the interaction with the transmembrane domain (TMD) during substrate translocation. DATABASE: Structural data are available in RCSB Protein Data Bank under the accession number(s) 6J9W, 6J9Y, 6JAD, 6JAG, 6JAH, 6JAI, 6JAL, 6JAM, 6JAN, 6JAO, 6JAP, 6JAQ, 6JAR, 6JAZ, 6JB0, 6JB4, 6JBA, 6JBB and 6JBE.

  • Organizational Affiliation

    Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, India.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
ABC transporter, periplasmic substrate-binding protein408Thermus thermophilus HB8Mutation(s): 1 
Gene Names: TTHA0356
Find proteins for Q5SLD7 (Thermus thermophilus (strain ATCC 27634 / DSM 579 / HB8))
Explore Q5SLD7 
Go to UniProtKB:  Q5SLD7
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ5SLD7
Sequence Annotations
  • Reference Sequence


Entity ID: 2
MoleculeChains Length2D Diagram Glycosylation3D Interactions
Glycosylation Resources
GlyTouCan:  G07411ON
GlyCosmos:  G07411ON
Biologically Interesting Molecules (External Reference) 1 Unique
Experimental Data & Validation

Experimental Data

  • Resolution: 1.63 Å
  • R-Value Free: 0.162 
  • R-Value Work: 0.137 
  • R-Value Observed: 0.138 
  • Space Group: P 41 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 85.13α = 90
b = 85.13β = 90
c = 145.54γ = 90
Software Package:
Software NamePurpose
HKL-3000data collection
iMOSFLMdata reduction
Aimlessdata scaling
Cootmodel building
PDB_EXTRACTdata extraction

Structure Validation

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Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
Department of Biotechnology (India)IndiaBT/563/NE/U-Excel/2016

Revision History  (Full details and data files)

  • Version 1.0: 2019-10-30
    Type: Initial release
  • Version 1.1: 2020-05-06
    Changes: Database references
  • Version 2.0: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Atomic model, Author supporting evidence, Data collection, Derived calculations, Non-polymer description, Structure summary
  • Version 2.1: 2023-11-22
    Changes: Data collection, Database references, Refinement description, Structure summary