Crystal Structure of GlfT2

Experimental Data Snapshot

  • Resolution: 2.45 Å
  • R-Value Free: 0.222 
  • R-Value Work: 0.185 
  • R-Value Observed: 0.187 

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This is version 1.3 of the entry. See complete history


Tetrameric Structure of the GlfT2 Galactofuranosyltransferase Reveals a Scaffold for the Assembly of Mycobacterial Arabinogalactan.

Wheatley, R.W.Zheng, R.B.Richards, M.R.Lowary, T.L.Ng, K.K.

(2012) J Biol Chem 287: 28132-28143

  • DOI: https://doi.org/10.1074/jbc.M112.347484
  • Primary Citation of Related Structures:  
    4FIX, 4FIY

  • PubMed Abstract: 

    Biosynthesis of the mycobacterial cell wall relies on the activities of many enzymes, including several glycosyltransferases (GTs). The polymerizing galactofuranosyltransferase GlfT2 (Rv3808c) synthesizes the bulk of the galactan portion of the mycolyl-arabinogalactan complex, which is the largest component of the mycobacterial cell wall. We used x-ray crystallography to determine the 2.45-Å resolution crystal structure of GlfT2, revealing an unprecedented multidomain structure in which an N-terminal β-barrel domain and two primarily α-helical C-terminal domains flank a central GT-A domain. The kidney-shaped protomers assemble into a C(4)-symmetric homotetramer with an open central core and a surface containing exposed hydrophobic and positively charged residues likely involved with membrane binding. The structure of a 3.1-Å resolution complex of GlfT2 with UDP reveals a distinctive mode of nucleotide recognition. In addition, models for the binding of UDP-galactofuranose and acceptor substrates in combination with site-directed mutagenesis and kinetic studies suggest a mechanism that explains the unique ability of GlfT2 to generate alternating β-(1→5) and β-(1→6) glycosidic linkages using a single active site. The topology imposed by docking a tetrameric assembly onto a membrane bilayer also provides novel insights into aspects of processivity and chain length regulation in this and possibly other polymerizing GTs.

  • Organizational Affiliation

    Alberta Glycomics Centre, University of Calgary, Calgary, Alberta T2N 1N4, Canada.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
UDP-galactofuranosyl transferase GlfT2
A, B
657Mycobacterium tuberculosis H37RvMutation(s): 0 
Gene Names: glfT2Rv3808cRV38308c
EC: 2.4.1
Membrane Entity: Yes 
Find proteins for O53585 (Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv))
Explore O53585 
Go to UniProtKB:  O53585
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupO53585
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.45 Å
  • R-Value Free: 0.222 
  • R-Value Work: 0.185 
  • R-Value Observed: 0.187 
  • Space Group: P 4 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 150.791α = 90
b = 150.791β = 90
c = 148.016γ = 90
Software Package:
Software NamePurpose
Blu-Icedata collection
PHENIXmodel building
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2012-06-20
    Type: Initial release
  • Version 1.1: 2012-08-29
    Changes: Database references
  • Version 1.2: 2012-10-17
    Changes: Derived calculations
  • Version 1.3: 2024-02-28
    Changes: Data collection, Database references, Derived calculations