1F0N

MYCOBACTERIUM TUBERCULOSIS ANTIGEN 85B


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • R-Value Free: 0.276 
  • R-Value Work: 0.194 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

An interfacial mechanism and a class of inhibitors inferred from two crystal structures of the Mycobacterium tuberculosis 30 kDa major secretory protein (Antigen 85B), a mycolyl transferase.

Anderson, D.H.Harth, G.Horwitz, M.A.Eisenberg, D.

(2001) J.Mol.Biol. 307: 671-681

  • DOI: 10.1006/jmbi.2001.4461
  • Primary Citation of Related Structures:  1F0P

  • PubMed Abstract: 
  • The Mycobacterium tuberculosis 30 kDa major secretory protein (antigen 85B) is the most abundant protein exported by M. tuberculosis, as well as a potent immunoprotective antigen and a leading drug target. A mycolyl transferase of 285 residues, it is ...

    The Mycobacterium tuberculosis 30 kDa major secretory protein (antigen 85B) is the most abundant protein exported by M. tuberculosis, as well as a potent immunoprotective antigen and a leading drug target. A mycolyl transferase of 285 residues, it is closely related to two other mycolyl transferases, each of molecular mass 32 kDa: antigen 85A and antigen 85C. All three catalyze transfer of the fatty acid mycolate from one trehalose monomycolate to another, resulting in trehalose dimycolate and free trehalose, thus helping to build the bacterial cell wall. We have determined two crystal structures of M. tuberculosis antigen 85B (ag85B), initially by molecular replacement using antigen 85C as a probe. The apo ag85B model is refined against 1.8 A data, to an R-factor of 0.196 (R(free) is 0.276), and includes all residues except the N-terminal Phe. The active site immobilizes a molecule of the cryoprotectant 2-methyl-2,4-pentanediol. Crystal growth with addition of trehalose resulted in a second ag85B crystal structure (1.9 A resolution; R-factor is 0.195; R(free) is 0.285). Trehalose binds in two sites at opposite ends of the active-site cleft. In our proposed mechanism model, the trehalose at the active site Ser126 represents the trehalose liberated by temporary esterification of Ser126, while the other trehalose represents the incoming trehalose monomycolate just prior to swinging over to the first trehalose site to displace the mycolate from its serine ester. Our proposed interfacial mechanism minimizes aqueous exposure of the apolar mycolates. Based on the trehalose-bound structure, we suggest a new class of antituberculous drugs, made by connecting two trehalose molecules by an amphipathic linker.


    Related Citations: 
    • Crystal Structure of the Secreted Form of Antigen 85C Reveals Potential Targets for Mycobacterial Drugs and Vaccines
      Ronning, D.R.,Klabunde, T.,Besra, G.S.,Vissa, V.D.,Belisle, J.T.,Sacchettini, J.C.
      (2000) Nat.Struct.Mol.Biol. 7: 141


    Organizational Affiliation

    UCLA-DOE Laboratory of Structural Biology and Molecular Medicine, University of California, Los Angeles, CA 90095-1570, USA. dha@mbi.ucla.edu




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
ANTIGEN 85B
A
285Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv)Gene Names: fbpB
EC: 2.3.1.122, 2.3.1.20
Find proteins for P9WQP1 (Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv))
Go to UniProtKB:  P9WQP1
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
MPD
Query on MPD

Download SDF File 
Download CCD File 
A
(4S)-2-METHYL-2,4-PENTANEDIOL
C6 H14 O2
SVTBMSDMJJWYQN-YFKPBYRVSA-N
 Ligand Interaction
MES
Query on MES

Download SDF File 
Download CCD File 
A
2-(N-MORPHOLINO)-ETHANESULFONIC ACID
C6 H13 N O4 S
SXGZJKUKBWWHRA-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • R-Value Free: 0.276 
  • R-Value Work: 0.194 
  • Space Group: P 31 2 1
Unit Cell:
Length (Å)Angle (°)
a = 73.210α = 90.00
b = 73.210β = 90.00
c = 92.544γ = 120.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
AMoREphasing
SHELXL-97refinement
DENZOdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2001-01-24
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2018-01-31
    Type: Experimental preparation