5HW4

Crystal structure of Escherichia coli 16S rRNA methyltransferase RsmI in complex with AdoMet


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.21 Å
  • R-Value Free: 0.230 
  • R-Value Work: 0.203 
  • R-Value Observed: 0.204 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Structural Insights into the Methylation of C1402 in 16S rRNA by Methyltransferase RsmI

Zhao, M.Zhang, H.Liu, G.Wang, L.Wang, J.Gao, Z.Dong, Y.Zhang, L.Gong, Y.

(2016) PLoS One 11: e0163816-e0163816

  • DOI: 10.1371/journal.pone.0163816
  • Structures With Same Primary Citation

  • PubMed Abstract: 
  • RsmI and RsmH are conserved S-Adenosylmethionine (AdoMet)-dependent methyltransferases (MTases) that are responsible for the 2'-O-methylation and N4-methylation of C1402 in bacterial 16S rRNA, respectively. Methylation of m4Cm1402 plays a role in fin ...

    RsmI and RsmH are conserved S-Adenosylmethionine (AdoMet)-dependent methyltransferases (MTases) that are responsible for the 2'-O-methylation and N4-methylation of C1402 in bacterial 16S rRNA, respectively. Methylation of m4Cm1402 plays a role in fine-tuning the shape and functions of the P-site to increase the decoding fidelity, and was recently found to contribute to the virulence of Staphylococcus aureus in host animals. Here we report the 2.20-Å crystal structure of homodimeric RsmI from Escherichia coli in complex with the cofactor AdoMet. RsmI consists of an N-terminal putative RNA-binding domain (NTD) and a C-terminal catalytic domain (CTD) with a Rossmann-like fold, and belongs to the class III MTase family. AdoMet is specifically bound into a negatively charged deep pocket formed by both domains by making extensive contacts. Structure-based mutagenesis and isothermal titration calorimetry (ITC) assays revealed Asp100 and Ala124 are vital for AdoMet-binding. Although the overall fold of RsmI shows remarkable similarities to the characterized MTases involved in vitamin B12 biosynthesis, it exhibits a distinct charge distribution especially around the AdoMet-binding pocket because of different substrate specificity. The docking model of RsmI-AdoMet-RNA ternary complex suggested a possible base-flipping mechanism of the substrate RNA that has been observed in several known RNA MTases. Our structural and biochemical studies provide novel insights into the catalytic mechanism of C1402 methylation in 16S rRNA.


    Organizational Affiliation

    Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, China.



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Ribosomal RNA small subunit methyltransferase I
A, B, C
248Escherichia coli K-12Mutation(s): 0 
Gene Names: rsmIyraLb3146JW3115
EC: 2.1.1.198
Find proteins for P67087 (Escherichia coli (strain K12))
Go to UniProtKB:  P67087
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SAM
Query on SAM

Download CCD File 
A, B, C
S-ADENOSYLMETHIONINE
C15 H22 N6 O5 S
MEFKEPWMEQBLKI-FCKMPRQPSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
SAMKa:  42900   M^-1  Binding MOAD
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.21 Å
  • R-Value Free: 0.230 
  • R-Value Work: 0.203 
  • R-Value Observed: 0.204 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 120.923α = 90
b = 155.27β = 93.89
c = 54.604γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
HKL-2000data reduction
HKL-2000data scaling
PHASERphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2016-10-19
    Type: Initial release
  • Version 1.1: 2017-08-16
    Changes: Database references, Derived calculations