1SFR

Crystal Structure of the Mycobacterium tuberculosis Antigen 85A Protein


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.7 Å
  • R-Value Free: 0.254 
  • R-Value Work: 0.222 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Mycobacterium tuberculosis Antigen 85A and 85C Structures Confirm Binding Orientation and Conserved Substrate Specificity

Ronning, D.R.Vissa, V.Besra, G.S.Belisle, J.T.Sacchettini, J.C.

(2004) J.Biol.Chem. 279: 36771-36777

  • DOI: 10.1074/jbc.M400811200
  • Primary Citation of Related Structures:  1VA5

  • PubMed Abstract: 
  • The maintenance of the highly hydrophobic cell wall is central to the survival of Mycobacterium tuberculosis within its host environment. The antigen 85 proteins (85A, 85B, and 85C) of M. tuberculosis help maintain the integrity of the cell wall 1) b ...

    The maintenance of the highly hydrophobic cell wall is central to the survival of Mycobacterium tuberculosis within its host environment. The antigen 85 proteins (85A, 85B, and 85C) of M. tuberculosis help maintain the integrity of the cell wall 1) by catalyzing the transfer of mycolic acids to the cell wall arabinogalactan and 2) through the synthesis of trehalose dimycolate (cord factor). Additionally, these secreted proteins allow for rapid invasion of alveolar macrophages via direct interactions between the host immune system and the invading bacillus. Here we describe two crystal structures: the structure of antigen 85C co-crystallized with octylthioglucoside as substrate, resolved to 2.0 A, and the crystal structure of antigen 85A, which was solved at a resolution of 2.7 A. The structure of 85C with the substrate analog identifies residues directly involved in substrate binding. Elucidation of the antigen 85A structure, the last of the three antigen 85 homologs to be solved, shows that the active sites of the three antigen 85 proteins are virtually identical, indicating that these share the same substrate. However, in contrast to the high level of conservation within the substrate-binding site and the active site, surface residues disparate from the active site are quite variable, indicating that three antigen 85 enzymes are needed to evade the host immune system.


    Organizational Affiliation

    Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843-2128, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Antigen 85-A
A, B, C
304Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv)Gene Names: fbpA (mpt44)
EC: 2.3.1.122, 2.3.1.20
Find proteins for P9WQP3 (Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv))
Go to UniProtKB:  P9WQP3
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.7 Å
  • R-Value Free: 0.254 
  • R-Value Work: 0.222 
  • Space Group: C 2 2 21
Unit Cell:
Length (Å)Angle (°)
a = 131.430α = 90.00
b = 288.662β = 90.00
c = 101.289γ = 90.00
Software Package:
Software NamePurpose
DENZOdata reduction
AMoREphasing
CNSrefinement
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2004-07-06
    Type: Initial release
  • Version 1.1: 2008-04-29
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance