3LO7

Crystal structure of PBPA from Mycobacterium tuberculosis


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.05 Å
  • R-Value Free: 0.252 
  • R-Value Work: 0.215 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Unusual conformation of the SxN motif in the crystal structure of penicillin-binding protein A from Mycobacterium tuberculosis.

Fedarovich, A.Nicholas, R.A.Davies, C.

(2010) J.Mol.Biol. 398: 54-65

  • DOI: 10.1016/j.jmb.2010.02.046

  • PubMed Abstract: 
  • PBPA from Mycobacterium tuberculosis is a class B-like penicillin-binding protein (PBP) that is not essential for cell growth in M. tuberculosis, but is important for proper cell division in Mycobacterium smegmatis. We have determined the crystal str ...

    PBPA from Mycobacterium tuberculosis is a class B-like penicillin-binding protein (PBP) that is not essential for cell growth in M. tuberculosis, but is important for proper cell division in Mycobacterium smegmatis. We have determined the crystal structure of PBPA at 2.05 A resolution, the first published structure of a PBP from this important pathogen. Compared to other PBPs, PBPA has a relatively small N-terminal domain, and conservation of a cluster of charged residues within this domain suggests that PBPA is more related to class B PBPs than previously inferred from sequence analysis. The C-terminal domain is a typical transpeptidase fold and contains the three conserved active-site motifs characteristic of penicillin-interacting enzymes. Whilst the arrangement of the SxxK and KTG motifs is similar to that observed in other PBPs, the SxN motif is markedly displaced away from the active site, such that its serine (Ser281) is not involved in hydrogen bonding with residues of the other two motifs. A disulfide bridge between Cys282 (the "x" of the SxN motif) and Cys266, which resides on an adjacent loop, may be responsible for this unusual conformation. Another interesting feature of the structure is a relatively long connection between beta 5 and alpha 11, which restricts the space available in the active site of PBPA and suggests that conformational changes would be required to accommodate peptide substrate or beta-lactam antibiotics during acylation. Finally, the structure shows that one of the two threonines postulated to be targets for phosphorylation is inaccessible (Thr362), whereas the other (Thr437) is well placed on a surface loop near the active site.


    Organizational Affiliation

    Department of Biochemistry and Molecular Biology, Medical University of South Carolina, 173 Ashley Avenue, Charleston, SC 29425, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Penicillin-binding protein A
A, B
483Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv)Mutation(s): 0 
Gene Names: pbpA
Find proteins for P9WKD1 (Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv))
Go to UniProtKB:  P9WKD1
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.05 Å
  • R-Value Free: 0.252 
  • R-Value Work: 0.215 
  • Space Group: P 61
Unit Cell:
Length (Å)Angle (°)
a = 120.600α = 90.00
b = 120.600β = 90.00
c = 92.200γ = 120.00
Software Package:
Software NamePurpose
REFMACrefinement
HKL-2000data reduction
MAR345data collection
SCALEPACKdata scaling
SOLVEphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2010-03-23
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance
  • Version 1.2: 2017-11-01
    Type: Refinement description