2E4G

RebH with bound L-Trp


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.08 Å
  • R-Value Free: 0.212 
  • R-Value Work: 0.186 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Chlorination by a long-lived intermediate in the mechanism of flavin-dependent halogenases

Yeh, E.Blasiak, L.C.Koglin, A.Drennan, C.L.Walsh, C.T.

(2007) Biochemistry 46: 1284-1292

  • DOI: 10.1021/bi0621213
  • Primary Citation of Related Structures:  2OAL, 2OAM

  • PubMed Abstract: 
  • The flavin-dependent halogenase RebH catalyzes the formation of 7-chlorotryptophan as the initial step in the biosynthesis of antitumor agent rebeccamycin. The reaction of FADH2, Cl-, and O2 in the active site generates the powerful oxidant HOCl, whi ...

    The flavin-dependent halogenase RebH catalyzes the formation of 7-chlorotryptophan as the initial step in the biosynthesis of antitumor agent rebeccamycin. The reaction of FADH2, Cl-, and O2 in the active site generates the powerful oxidant HOCl, which was presumed to carry out the chlorination reaction. Herein, we demonstrate the formation of a long-lived chlorinating intermediate (t1/2 = 63 h at 4 degrees C) when RebH, FADH2, Cl-, and O2 react in the absence of substrate tryptophan. This intermediate remained on the enzyme after removal of FAD and transferred chlorine to tryptophan with kinetically competent rates. The identity of this intermediate is suggested by the X-ray crystal structure of RebH, which revealed an active site Lys79 located in a central position between flavin and tryptophan binding sites and just 4.1 A above C7 of tryptophan. The chlorinating species is proposed to be a Lys-epsilonNH-Cl (lysine chloramine) from reaction of enzyme-generated HOCl with the active site Lys79. This covalent enzyme chloramine likely plays a key role in directing regiospecific chlorination of substrate in this important class of biosynthetic enzymes.


    Organizational Affiliation

    Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Tryptophan halogenase
A, B
550Lechevalieria aerocolonigenesGene Names: rebH (rbmJ)
EC: 1.14.19.9
Find proteins for Q8KHZ8 (Lechevalieria aerocolonigenes)
Go to UniProtKB:  Q8KHZ8
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
TRP
Query on TRP

Download SDF File 
Download CCD File 
A, B
TRYPTOPHAN
C11 H12 N2 O2
QIVBCDIJIAJPQS-VIFPVBQESA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.08 Å
  • R-Value Free: 0.212 
  • R-Value Work: 0.186 
  • Space Group: P 62
Unit Cell:
Length (Å)Angle (°)
a = 114.750α = 90.00
b = 114.750β = 90.00
c = 231.233γ = 120.00
Software Package:
Software NamePurpose
PHASERphasing
HKL-2000data reduction
HKL-2000data scaling
HKL-2000data collection
SCALEPACKdata scaling
DENZOdata reduction
PDB_EXTRACTdata extraction
CNSrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-02-13
    Type: Initial release
  • Version 1.1: 2008-04-30
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2017-10-11
    Type: Refinement description