1S6L

Solution structure of MerB, the Organomercurial Lyase involved in the bacterial mercury resistance system


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 55 
  • Conformers Submitted: 20 
  • Selection Criteria: The submitted models are the 20 structures with no upper bound violation greater that 0.3 armstrongs and no dihedral angle restraint violation greater than 2 degrees and with the lowest energies. 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

NMR structural studies reveal a novel protein fold for MerB, the organomercurial lyase involved in the bacterial mercury resistance system.

Di Lello, P.Benison, G.C.Valafar, H.Pitts, K.E.Summers, A.O.Legault, P.Omichinski, J.G.

(2004) Biochemistry 43: 8322-8332

  • DOI: 10.1021/bi049669z

  • PubMed Abstract: 
  • Mercury resistant bacteria have developed a system of two enzymes (MerA and MerB), which allows them to efficiently detoxify both ionic and organomercurial compounds. The organomercurial lyase (MerB) catalyzes the protonolysis of the carbon-mercury b ...

    Mercury resistant bacteria have developed a system of two enzymes (MerA and MerB), which allows them to efficiently detoxify both ionic and organomercurial compounds. The organomercurial lyase (MerB) catalyzes the protonolysis of the carbon-mercury bond resulting in the formation of ionic mercury and a reduced hydrocarbon. The ionic mercury [Hg(II)] is subsequently reduced to the less reactive elemental mercury [Hg(0)] by a specific mercuric reductase (MerA). To better understand MerB's unique enzymatic activity, we used nuclear magnetic resonance (NMR) spectroscopy to determine the structure of the free enzyme. MerB is characterized by a novel protein fold consisting of three noninteracting antiparallel beta-sheets surrounded by six alpha-helices. By comparing the NMR data of free MerB and the MerB/Hg/DTT complex, we identified a set of residues that likely define a Hg/DTT binding site. These residues cluster around two cysteines (C(96) and C(159)) that are crucial to MerB's catalytic activity. A detailed analysis of the structure revealed the presence of an extensive hydrophobic groove adjacent to this Hg/DTT binding site. This extensive hydrophobic groove has the potential to interact with the hydrocarbon moiety of a wide variety of substrates and may explain the broad substrate specificity of MerB.


    Related Citations: 
    • 1H, 15N, and 13C resonance assignment of the 23 kDa organomercurial lyase MerB in its free and mercury-bound forms
      Di Lello, P.,Benison, G.C.,Omichinski, J.G.,Legault, P.
      (2004) J.Biomol.NMR 29: 457


    Organizational Affiliation

    Department of Biochemistry & Molecular Biology, University of Georgia, Athens, Georgia 30602, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Alkylmercury lyase
A
212Escherichia coliMutation(s): 0 
Gene Names: merB
EC: 4.99.1.2
Find proteins for P77072 (Escherichia coli)
Go to UniProtKB:  P77072
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 55 
  • Conformers Submitted: 20 
  • Selection Criteria: The submitted models are the 20 structures with no upper bound violation greater that 0.3 armstrongs and no dihedral angle restraint violation greater than 2 degrees and with the lowest energies. 
  • Olderado: 1S6L Olderado

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2005-04-19
    Type: Initial release
  • Version 1.1: 2008-04-29
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance