2GUF

In meso crystal structure of the cobalamin transporter, BtuB


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.225 
  • R-Value Work: 0.189 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

In Meso Structure of the Cobalamin Transporter, BtuB, at 1.95 A Resolution.

Cherezov, V.Yamashita, E.Liu, W.Zhalnina, M.Cramer, W.A.Caffrey, M.

(2006) J.Mol.Biol. 364: 716-734

  • DOI: 10.1016/j.jmb.2006.09.022

  • PubMed Abstract: 
  • Crystals of the apo form of the vitamin B12 and colicin receptor, BtuB, that diffract to 1.95 A have been grown by the membrane-based in meso technique. The structure of the protein differs in several details from that of its counterpart grown by the ...

    Crystals of the apo form of the vitamin B12 and colicin receptor, BtuB, that diffract to 1.95 A have been grown by the membrane-based in meso technique. The structure of the protein differs in several details from that of its counterpart grown by the more traditional, detergent-based (in surfo) method. Some of these differences include (i) the five N-terminal residues are resolved in meso, (ii) residues 57-62 in the hatch domain and residues 574-581 in loop 21-22 are disordered in meso and are ordered in surfo, (iii) residues 278-287 in loop 7-8 are resolved in meso, (iv) residues 324-331 in loop 9-10, 396-411 in loop 13-14, 442-458 in loop 15-16 and 526-541 in loop 19-20 have large differences in position between the two crystal forms, as have residues 86-96 in the hatch domain, and (v) the conformation of residues 6 and 7 in the Ton box (considered critical to signal transduction and substrate transport) are entirely different in the two structures. Importantly, the in meso orientation of residues 6 and 7 is similar to that of the vitamin B12-charged state. These data suggest that the "substrate-induced" 180 degrees -rotation of residues 6 and 7 reported in the literature may not be a unique signalling event. The extent to which these findings agree with structural, dynamic and functional insights gleaned from site-directed spin labelling and electron paramagnetic resonance measurements is evaluated. Packing in in meso grown crystals is dense and layered, consistent with the current model for crystallogenesis of membrane proteins in lipidic mesophases. Layered packing has been used to locate the transmembrane hydrophobic surface of the protein. Generally, this is consistent with tryptophan, tyrosine, lipid and CalphaB-factor distributions in the protein, and with predictions based on transfer free energy calculations.


    Organizational Affiliation

    Department of Chemistry, The Ohio State University, Columbus, OH 43210, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Vitamin B12 transporter btuB
A
594Escherichia coli (strain K12)Mutation(s): 0 
Gene Names: btuB (bfe, cer, dcrC)
Membrane protein
mpstruct
Group: 
TRANSMEMBRANE PROTEINS: BETA-BARREL
Sub Group: 
Beta-Barrel Membrane Proteins: Monomeric/Dimeric
Protein: 
apo BtuB cobalamin transporter
Find proteins for P06129 (Escherichia coli (strain K12))
Go to UniProtKB:  P06129
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
FMT
Query on FMT

Download SDF File 
Download CCD File 
A
FORMIC ACID
C H2 O2
BDAGIHXWWSANSR-UHFFFAOYSA-N
 Ligand Interaction
MPG
Query on MPG

Download SDF File 
Download CCD File 
A
[(Z)-octadec-9-enyl] (2R)-2,3-bis(oxidanyl)propanoate
C21 H40 O4
JPJYKWFFJCWMPK-GDCKJWNLSA-N
 Ligand Interaction
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
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.95 Å
  • R-Value Free: 0.225 
  • R-Value Work: 0.189 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 72.610α = 90.00
b = 80.877β = 90.00
c = 118.681γ = 90.00
Software Package:
Software NamePurpose
HKL-2000data scaling
REFMACrefinement
MOLREPphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2006-12-05
    Type: Initial release
  • Version 1.1: 2008-05-01
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Advisory, Version format compliance