1JFU

CRYSTAL STRUCTURE OF THE SOLUBLE DOMAIN OF TLPA FROM BRADYRHIZOBIUM JAPONICUM


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.6 Å
  • R-Value Free: 0.234 
  • R-Value Work: 0.181 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structure of the soluble domain of a membrane-anchored thioredoxin-like protein from Bradyrhizobium japonicum reveals unusual properties.

Capitani, G.Rossmann, R.Sargent, D.F.Grutter, M.G.Richmond, T.J.Hennecke, H.

(2001) J.Mol.Biol. 311: 1037-1048

  • DOI: 10.1006/jmbi.2001.4913

  • PubMed Abstract: 
  • TlpA is an unusual thioredoxin-like protein present in the nitrogen-fixing soil bacterium Bradyrhizobium japonicum. A hydrophobic N-terminal transmembrane domain anchors it to the cytoplasmic membrane, whereby the hydrophilic thioredoxin domain becom ...

    TlpA is an unusual thioredoxin-like protein present in the nitrogen-fixing soil bacterium Bradyrhizobium japonicum. A hydrophobic N-terminal transmembrane domain anchors it to the cytoplasmic membrane, whereby the hydrophilic thioredoxin domain becomes exposed to the periplasmic space. There, TlpA catalyses an essential reaction, probably a reduction, in the biogenesis of cytochrome aa(3). The soluble thioredoxin domain (TlpA(sol)), devoid of the membrane anchor, was purified and crystallized. Oxidized TlpA(sol) crystallized as a non-covalent dimer in the space group P2(1)2(1)2(1). The X-ray structure analysis was carried out by isomorphous replacement using a xenon derivative. This resulted in a high-resolution (1.6 A) three-dimensional structure that displayed all of the features of a classical thioredoxin fold. A number of peculiar structural details were uncovered: (i) Only one of the two active-site-cysteine sulphurs (Cys72, the one closer to the N terminus) is exposed on the surface, making it the likely nucleophile for the reduction of target proteins. (ii) TlpA(sol) possesses a unique structural disulphide bond, formed between Cys10 and Cys155, which connects an unprecedented N-terminal alpha helix with a beta sheet near the C terminus. (iii) An insertion of about 25 amino acid residues, not found in the thioredoxin prototype of Escherichia coli, contributes only marginally to the thioredoxin fold, but forms an extra, surface-exposed alpha helix. This region plus another surface-exposed stretch (-Ile-Gly-Arg-Ala-), which is absent even in the closest TlpA relatives, might be considered as specificity determinants for the recognition of target proteins in the periplasm. The TlpA(sol) structure paves the way towards unraveling important structure-function relationships by rational mutagenesis.


    Organizational Affiliation

    Biochemisches Institut, Universität Zürich, CH-8057 Zürich, Switzerland.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
THIOL:DISULFIDE INTERCHANGE PROTEIN TLPA
A, B
186Bradyrhizobium diazoefficiens (strain JCM 10833 / IAM 13628 / NBRC 14792 / USDA 110)Gene Names: tlpA
Find proteins for P43221 (Bradyrhizobium diazoefficiens (strain JCM 10833 / IAM 13628 / NBRC 14792 / USDA 110))
Go to UniProtKB:  P43221
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.6 Å
  • R-Value Free: 0.234 
  • R-Value Work: 0.181 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 50.620α = 90.00
b = 75.150β = 90.00
c = 82.990γ = 90.00
Software Package:
Software NamePurpose
SHARPphasing
SCALEPACKdata scaling
DENZOdata reduction
REFMACrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2001-09-19
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance