3MTE

Crystal Structure of 16S rRNA Methyltranferase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.805 Å
  • R-Value Free: 0.204 
  • R-Value Work: 0.173 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Structural insights into the function of aminoglycoside-resistance A1408 16S rRNA methyltransferases from antibiotic-producing and human pathogenic bacteria.

Macmaster, R.Zelinskaya, N.Savic, M.Rankin, C.R.Conn, G.L.

(2010) Nucleic Acids Res. 38: 7791-7799

  • DOI: 10.1093/nar/gkq627
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • X-ray crystal structures were determined of the broad-spectrum aminoglycoside-resistance A1408 16S rRNA methyltransferases KamB and NpmA, from the aminoglycoside-producer Streptoalloteichus tenebrarius and human pathogenic Escherichia coli, respectiv ...

    X-ray crystal structures were determined of the broad-spectrum aminoglycoside-resistance A1408 16S rRNA methyltransferases KamB and NpmA, from the aminoglycoside-producer Streptoalloteichus tenebrarius and human pathogenic Escherichia coli, respectively. Consistent with their common function, both are Class I methyltransferases with additional highly conserved structural motifs that embellish the core SAM-binding fold. In overall structure, the A1408 rRNA methyltransferase were found to be most similar to a second family of Class I methyltransferases of distinct substrate specificity (m(7)G46 tRNA). Critical residues for A1408 rRNA methyltransferase activity were experimentally defined using protein mutagenesis and bacterial growth assays with kanamycin. Essential residues for SAM coenzyme binding and an extended protein surface that likely interacts with the 30S ribosomal subunit were thus revealed. The structures also suggest potential mechanisms of A1408 target nucleotide selection and positioning. We propose that a dynamic extended loop structure that is positioned adjacent to both the bound SAM and a functionally critical structural motif may mediate concerted conformational changes in rRNA and protein that underpin the specificity of target selection and activation of methyltransferase activity. These new structures provide important new insights that may provide a starting point for strategies to inhibit these emerging causes of pathogenic bacterial resistance to aminoglycosides.


    Organizational Affiliation

    Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
16S rRNA methylase
A, B
222Escherichia 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
SAM
Query on SAM

Download SDF File 
Download CCD File 
A, B
S-ADENOSYLMETHIONINE
C15 H22 N6 O5 S
MEFKEPWMEQBLKI-FCKMPRQPSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.805 Å
  • R-Value Free: 0.204 
  • R-Value Work: 0.173 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 49.651α = 90.00
b = 59.816β = 96.29
c = 91.697γ = 90.00
Software Package:
Software NamePurpose
PHENIXrefinement
HKL-2000data reduction
PHASERphasing
HKL-2000data collection
HKL-2000data scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2010-12-08
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance