3SPA

Crystal Structure of Human Mitochondrial RNA Polymerase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.231 
  • R-Value Work: 0.185 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structure of human mitochondrial RNA polymerase

Ringel, R.Sologub, M.Morozov, Y.I.Litonin, D.Cramer, P.Temiakov, D.

(2011) Nature 478: 269-273

  • DOI: 10.1038/nature10435

  • PubMed Abstract: 
  • Transcription of the mitochondrial genome is performed by a single-subunit RNA polymerase (mtRNAP) that is distantly related to the RNAP of bacteriophage T7, the pol I family of DNA polymerases, and single-subunit RNAPs from chloroplasts. Whereas T7 ...

    Transcription of the mitochondrial genome is performed by a single-subunit RNA polymerase (mtRNAP) that is distantly related to the RNAP of bacteriophage T7, the pol I family of DNA polymerases, and single-subunit RNAPs from chloroplasts. Whereas T7 RNAP can initiate transcription by itself, mtRNAP requires the factors TFAM and TFB2M for binding and melting promoter DNA. TFAM is an abundant protein that binds and bends promoter DNA 15-40 base pairs upstream of the transcription start site, and stimulates the recruitment of mtRNAP and TFB2M to the promoter. TFB2M assists mtRNAP in promoter melting and reaches the active site of mtRNAP to interact with the first base pair of the RNA-DNA hybrid. Here we report the X-ray structure of human mtRNAP at 2.5 Å resolution, which reveals a T7-like catalytic carboxy-terminal domain, an amino-terminal domain that remotely resembles the T7 promoter-binding domain, a novel pentatricopeptide repeat domain, and a flexible N-terminal extension. The pentatricopeptide repeat domain sequesters an AT-rich recognition loop, which binds promoter DNA in T7 RNAP, probably explaining the need for TFAM during promoter binding. Consistent with this, substitution of a conserved arginine residue in the AT-rich recognition loop, or release of this loop by deletion of the N-terminal part of mtRNAP, had no effect on transcription. The fingers domain and the intercalating hairpin, which melts DNA in phage RNAPs, are repositioned, explaining the need for TFB2M during promoter melting. Our results provide a new venue for the mechanistic analysis of mitochondrial transcription. They also indicate how an early phage-like mtRNAP lost functions in promoter binding and melting, which were provided by initiation factors in trans during evolution, to enable mitochondrial gene regulation and the adaptation of mitochondrial function to changes in the environment.


    Organizational Affiliation

    Gene Center and Department of Biochemistry, Center for Integrated Protein Science Munich, Ludwig-Maximilians-Universität München, Feodor-Lynen-Strasse 25, 81377 Munich, Germany.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
DNA-directed RNA polymerase, mitochondrial
A
1134Homo sapiensMutation(s): 1 
Gene Names: POLRMT
EC: 2.7.7.6
Find proteins for O00411 (Homo sapiens)
Go to Gene View: POLRMT
Go to UniProtKB:  O00411
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Nonamer peptide
B
9N/AMutation(s): 0 
Protein Feature View is not available: No corresponding UniProt sequence found.
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

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Download CCD File 
A
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
CL
Query on CL

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Download CCD File 
A
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
GOL
Query on GOL

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Download CCD File 
A
GLYCEROL
GLYCERIN; PROPANE-1,2,3-TRIOL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
UNK
Query on UNK
B
L-PEPTIDE LINKINGC4 H9 N O2

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Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.231 
  • R-Value Work: 0.185 
  • Space Group: I 41
Unit Cell:
Length (Å)Angle (°)
a = 211.258α = 90.00
b = 211.258β = 90.00
c = 60.461γ = 90.00
Software Package:
Software NamePurpose
BUSTERrefinement
PHASERphasing
SCALAdata scaling
MOSFLMdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2011-09-28
    Type: Initial release
  • Version 1.1: 2011-10-19
    Type: Database references
  • Version 1.2: 2017-11-08
    Type: Refinement description