3P2E

Structure of an antibiotic related Methyltransferase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.68 Å
  • R-Value Free: 0.232 
  • R-Value Work: 0.197 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Structural basis for the methylation of A1408 in 16S rRNA by a panaminoglycoside resistance methyltransferase NpmA from a clinical isolate and analysis of the NpmA interactions with the 30S ribosomal subunit.

Husain, N.Obranic, S.Koscinski, L.Seetharaman, J.Babic, F.Bujnicki, J.M.Maravic-Vlahovicek, G.Sivaraman, J.

(2010) Nucleic Acids Res. --: --

  • DOI: 10.1093/nar/gkq1033
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • NpmA, a methyltransferase that confers resistance to aminoglycosides was identified in an Escherichia coli clinical isolate. It belongs to the kanamycin-apramycin methyltransferase (Kam) family and specifically methylates the 16S rRNA at the N1 posit ...

    NpmA, a methyltransferase that confers resistance to aminoglycosides was identified in an Escherichia coli clinical isolate. It belongs to the kanamycin-apramycin methyltransferase (Kam) family and specifically methylates the 16S rRNA at the N1 position of A1408. We determined the structures of apo-NpmA and its complexes with S-adenosylmethionine (AdoMet) and S-adenosylhomocysteine (AdoHcy) at 2.4, 2.7 and 1.68 Å, respectively. We generated a number of NpmA variants with alanine substitutions and studied their ability to bind the cofactor, to methylate A1408 in the 30S subunit, and to confer resistance to kanamycin in vivo. Residues D30, W107 and W197 were found to be essential. We have also analyzed the interactions between NpmA and the 30S subunit by footprinting experiments and computational docking. Helices 24, 42 and 44 were found to be the main NpmA-binding site. Both experimental and theoretical analyses suggest that NpmA flips out the target nucleotide A1408 to carry out the methylation. NpmA is plasmid-encoded and can be transferred between pathogenic bacteria; therefore it poses a threat to the successful use of aminoglycosides in clinical practice. The results presented here will assist in the development of specific NpmA inhibitors that could restore the potential of aminoglycoside antibiotics.


    Organizational Affiliation

    Department of Biological Sciences, 14 Science drive 4, National University of Singapore, Singapore.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
16S rRNA methylase
A, B
225Escherichia coliMutation(s): 0 
Gene Names: npmA
EC: 2.1.1.180
Find proteins for A8C927 (Escherichia coli)
Go to UniProtKB:  A8C927
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SAH
Query on SAH

Download SDF File 
Download CCD File 
A, B
S-ADENOSYL-L-HOMOCYSTEINE
C14 H20 N6 O5 S
ZJUKTBDSGOFHSH-WFMPWKQPSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
SAHKd: 600 nM BINDINGMOAD
SAHKd: 600 nM PDBBIND
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.68 Å
  • R-Value Free: 0.232 
  • R-Value Work: 0.197 
  • Space Group: P 43
Unit Cell:
Length (Å)Angle (°)
a = 64.985α = 90.00
b = 64.985β = 90.00
c = 108.424γ = 90.00
Software Package:
Software NamePurpose
CNSrefinement
SCALEPACKdata scaling
PDB_EXTRACTdata extraction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2010-11-17
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance