3TLY

Microcin C7 self immunity protein MccF active site mutant S118A/N220A/K247A in the apo state


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.201 
  • R-Value Work: 0.172 
  • R-Value Observed: 0.173 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report


This is version 1.4 of the entry. See complete history


Literature

Structure and function of a serine carboxypeptidase adapted for degradation of the protein synthesis antibiotic microcin C7.

Agarwal, V.Tikhonov, A.Metlitskaya, A.Severinov, K.Nair, S.K.

(2012) Proc Natl Acad Sci U S A 109: 4425-4430

  • DOI: https://doi.org/10.1073/pnas.1114224109
  • Primary Citation of Related Structures:  
    3TLA, 3TLB, 3TLC, 3TLE, 3TLG, 3TLY, 3TLZ

  • PubMed Abstract: 

    Several classes of naturally occurring antimicrobials exert their antibiotic activity by specifically targeting aminoacyl-tRNA synthetases, validating these enzymes as drug targets. The aspartyl tRNA synthetase "Trojan horse" inhibitor microcin C7 (McC7) consists of a nonhydrolyzable aspartyl-adenylate conjugated to a hexapeptide carrier that facilitates active import into bacterial cells through an oligopeptide transport system. Subsequent proteolytic processing releases the toxic compound inside the cell. Producing strains of McC7 must protect themselves against autotoxicity that may result from premature processing. The mccF gene confers resistance against endogenous and exogenous McC7 by hydrolyzing the amide bond that connects the peptide and nucleotide moieties of McC7. We present here crystal structures of MccF, in complex with various ligands. The MccF structure is similar to that of dipeptide ld-carboxypeptidase, but with an additional loop proximal to the active site that serves as the primary determinant for recognition of adenylated substrates. Wild-type MccF only hydrolyzes the naturally occurring aspartyl phosphoramidate McC7 and synthetic peptidyl sulfamoyl adenylates that contain anionic side chains. We show that substitutions of two active site MccF residues result in a specificity switch toward aromatic aminoacyl-adenylate substrates. These results suggest how MccF-like enzymes may be used to avert various toxic aminoacyl-adenylates that accumulate during antibiotic biosynthesis or in normal metabolism of the cell.


  • Organizational Affiliation

    Center for Biophysics and Computational Biology, Institute for Genomic Biology, and Department of Biochemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, IL 61801, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
MccF
A, B
371Escherichia coliMutation(s): 3 
Gene Names: mccF
UniProt
Find proteins for Q47511 (Escherichia coli)
Explore Q47511 
Go to UniProtKB:  Q47511
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ47511
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.201 
  • R-Value Work: 0.172 
  • R-Value Observed: 0.173 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 54.422α = 90
b = 85.658β = 101.24
c = 73.016γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
REFMACrefinement
PDB_EXTRACTdata extraction

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2012-02-29
    Type: Initial release
  • Version 1.1: 2012-03-28
    Changes: Database references
  • Version 1.2: 2012-04-04
    Changes: Database references
  • Version 1.3: 2017-11-08
    Changes: Refinement description
  • Version 1.4: 2023-09-13
    Changes: Data collection, Database references, Derived calculations, Refinement description