1RR7

Crystal structure of the Middle Operon Regulator protein of Bacteriophage Mu


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.20 Å
  • R-Value Free: 0.268 
  • R-Value Work: 0.252 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Crystal structure of the Mor protein of bacteriophage Mu, a member of the Mor/C family of transcription activators.

Kumaraswami, M.Howe, M.M.Park, H.W.

(2004) J Biol Chem 279: 16581-16590

  • DOI: 10.1074/jbc.M313555200
  • Structures With Same Primary Citation

  • PubMed Abstract: 
  • Transcription from the middle promoter, Pm, of bacteriophage Mu requires the phage-encoded activator protein Mor and bacterial RNA polymerase. Mor is a sequence-specific DNA-binding protein that mediates transcription activation through its interactions with the C-terminal domains of the alpha and sigma subunits of bacterial RNA polymerase ...

    Transcription from the middle promoter, Pm, of bacteriophage Mu requires the phage-encoded activator protein Mor and bacterial RNA polymerase. Mor is a sequence-specific DNA-binding protein that mediates transcription activation through its interactions with the C-terminal domains of the alpha and sigma subunits of bacterial RNA polymerase. Here we present the first structure for a member of the Mor/C family of transcription activators, the crystal structure of Mor to 2.2-A resolution. Each monomer of the Mor dimer is composed of two domains, the N-terminal dimerization domain and C-terminal DNA-binding domain, which are connected by a linker containing a beta strand. The N-terminal dimerization domain has an unusual mode of dimerization; helices alpha1 and alpha2 of both monomers are intertwined to form a four-helix bundle, generating a hydrophobic core that is further stabilized by antiparallel interactions between the two beta strands. Mutational analysis of key leucine residues in helix alpha1 demonstrated a role for this hydrophobic core in protein solubility and function. The C-terminal domain has a classical helix-turn-helix DNA-binding motif that is located at opposite ends of the elongated dimer. Since the distance between the two helix-turn-helix motifs is too great to allow binding to two adjacent major grooves of the 16-bp Mor-binding site, we propose that conformational changes in the protein and DNA will be required for Mor to interact with the DNA. The highly conserved glycines flanking the beta strand may act as pivot points, facilitating the conformational changes of Mor, and the DNA may be bent.


    Organizational Affiliation

    Department of Molecular Sciences, University of Tennessee Health Science Center, Memphis, Tennessee 38163, USA.



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Middle operon regulatorA129Escherichia virus MuMutation(s): 0 
Gene Names: morMup17
Find proteins for P23848 (Escherichia phage Mu)
Explore P23848 
Go to UniProtKB:  P23848
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PT
Query on PT

Download CCD File 
A
PLATINUM (II) ION
Pt
HRGDZIGMBDGFTC-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.20 Å
  • R-Value Free: 0.268 
  • R-Value Work: 0.252 
  • Space Group: P 32 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 81.631α = 90
b = 81.631β = 90
c = 44.843γ = 120
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
SOLVEphasing
RESOLVEmodel building
CNSrefinement
RESOLVEphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2004-08-17
    Type: Initial release
  • Version 1.1: 2008-04-29
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Derived calculations, Version format compliance