1G9X

CHARACTERIZATION OF THE TWINNING STRUCTURE OF MJ1267, AN ATP-BINDING CASSETTE OF AN ABC TRANSPORTER


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.6 Å
  • R-Value Free: 0.279 
  • R-Value Work: 0.153 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structural characterization of an MJ1267 ATP-binding cassette crystal with a complex pattern of twinning caused by promiscuous fiber packing.

Yuan, Y.R.Martsinkevich, O.Hunt, J.F.

(2003) Acta Crystallogr.,Sect.D 59: 225-238


  • PubMed Abstract: 
  • ATP-binding cassettes represent the motor domains in ABC transporters, a superfamily of integral membrane-protein pumps that couple the hydrolysis of ATP to transmembrane solute translocation. A crystal of a Mg-ADP complex of the MJ1267 ATP-binding c ...

    ATP-binding cassettes represent the motor domains in ABC transporters, a superfamily of integral membrane-protein pumps that couple the hydrolysis of ATP to transmembrane solute translocation. A crystal of a Mg-ADP complex of the MJ1267 ATP-binding cassette was obtained that produced a diffraction pattern characterized by pathological streaking of the spots in the a* x b* plane. While the Laue symmetry of the diffraction pattern was P3;1m, the crystal was determined to be twinned based on intensity statistics, molecular-replacement analysis and difference Fourier analysis of an engineered single-site methylmercury derivative. The unit cell contains three similar 3(1) fibers, with two of them related by primarily translational non-crystallographic symmetry (NCS) and the third related to the first two by approximate twofold screw operations whose rotational components are very similar to the twinning operator. The promiscuous packing of these 3(1) fibers, which make both parallel and antiparallel interactions in the primary crystal lattice, can explain the twinning tendency based on the ability of the twin-related lattices to interact with one another while making only one slightly sub-optimal intermolecular contact per unit cell in the boundary region. The promiscuous fiber packing can also explain the streaking in the diffraction pattern based on the ability to form a variety of different lattices with similar inter-fiber packing interactions. The crystal structure was refined as a twin in space group P3(1) using the program CNS, yielding a free R factor of 28.9% at 2.6 A and a refined twin fraction of 0.50. The structure shows a rigid-body rotation of the ABC-transporter-specific alpha-helical subdomain (ABCalpha subdomain) in MJ1267 compared with the conformation observed for the same protein in a C2 crystal lattice; this observation suggests that the ABCalpha subdomain is flexibly attached to the F1-type ATP-binding core of the ATP-binding cassette when Mg-ADP is bound at the active site.


    Organizational Affiliation

    Department of Biological Sciences, 702A Fairchild Center, MC2434, Columbia University, New York, NY 10027, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
HIGH-AFFINITY BRANCHED-CHAIN AMINO ACID TRANSPORT ATP-BINDING PROTEIN
A, B, C
257Methanocaldococcus jannaschii (strain ATCC 43067 / DSM 2661 / JAL-1 / JCM 10045 / NBRC 100440)Gene Names: livG
Find proteins for Q58663 (Methanocaldococcus jannaschii (strain ATCC 43067 / DSM 2661 / JAL-1 / JCM 10045 / NBRC 100440))
Go to UniProtKB:  Q58663
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ADP
Query on ADP

Download SDF File 
Download CCD File 
A, B, C
ADENOSINE-5'-DIPHOSPHATE
C10 H15 N5 O10 P2
XTWYTFMLZFPYCI-KQYNXXCUSA-N
 Ligand Interaction
MMC
Query on MMC

Download SDF File 
Download CCD File 
A, B, C
METHYL MERCURY ION
C H3 Hg
DBUXSCUEGJMZAE-UHFFFAOYSA-N
 Ligand Interaction
MG
Query on MG

Download SDF File 
Download CCD File 
A, B, C
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.6 Å
  • R-Value Free: 0.279 
  • R-Value Work: 0.153 
  • Space Group: P 31
Unit Cell:
Length (Å)Angle (°)
a = 117.310α = 90.00
b = 117.310β = 90.00
c = 42.190γ = 120.00
Software Package:
Software NamePurpose
AMoREphasing
DENZOdata reduction
CNSrefinement
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2003-02-11
    Type: Initial release
  • Version 1.1: 2008-04-01
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance