Transition metal inhibition and structural refinement of the M. tuberculosis esterase, Rv0045c

Experimental Data Snapshot

  • Resolution: 2.00 Å
  • R-Value Free: 0.250 
  • R-Value Work: 0.207 
  • R-Value Observed: 0.209 

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Transition metal cation inhibition of Mycobacterium tuberculosis esterase RV0045C.

Bowles, I.E.Pool, E.H.Lancaster, B.S.Lawson, E.K.Savas, C.P.Kartje, Z.J.Severinac, L.Cho, D.H.Macbeth, M.R.Johnson, R.J.Hoops, G.C.

(2021) Protein Sci 30: 1554-1565

  • DOI: https://doi.org/10.1002/pro.4089
  • Primary Citation of Related Structures:  
    6WYM, 6WYN

  • PubMed Abstract: 

    Mycobacterium tuberculosis virulence is highly metal-dependent with metal availability modulating the shift from the dormant to active states of M. tuberculosis infection. Rv0045c from M. tuberculosis is a proposed metabolic serine hydrolase whose folded stability is dependent on divalent metal concentration. Herein, we measured the divalent metal inhibition profile of the enzymatic activity of Rv0045c and found specific divalent transition metal cations (Cu 2+  ≥ Zn 2+  > Ni 2+  > Co 2+ ) strongly inhibited its enzymatic activity. The metal cations bind allosterically, largely affecting values for k cat rather than K M . Removal of the artificial N-terminal 6xHis-tag did not change the metal-dependent inhibition, indicating that the allosteric inhibition site is native to Rv0045c. To isolate the site of this allosteric regulation in Rv0045c, the structures of Rv0045c were determined at 1.8 Å and 2.0 Å resolution in the presence and absence of Zn 2+ with each structure containing a previously unresolved dynamic loop spanning the binding pocket. Through the combination of structural analysis with and without zinc and targeted mutagenesis, this metal-dependent inhibition was traced to multiple chelating residues (H202A/E204A) on a flexible loop, suggesting dynamic allosteric regulation of Rv0045c by divalent metals. Although serine hydrolases like Rv0045c are a large and diverse enzyme superfamily, this is the first structural confirmation of allosteric regulation of their enzymatic activity by divalent metals.

  • Organizational Affiliation

    Department of Chemistry and Biochemistry, Butler University, Indianapolis, Indiana, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Possible hydrolase331Mycobacterium tuberculosis H37RvMutation(s): 0 
Gene Names: Rv0045c
Find proteins for I6XU97 (Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv))
Explore I6XU97 
Go to UniProtKB:  I6XU97
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupI6XU97
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on CL

Download Ideal Coordinates CCD File 
Experimental Data & Validation

Experimental Data

  • Resolution: 2.00 Å
  • R-Value Free: 0.250 
  • R-Value Work: 0.207 
  • R-Value Observed: 0.209 
  • Space Group: P 31 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 130.618α = 90
b = 130.618β = 90
c = 48.814γ = 120
Software Package:
Software NamePurpose
PDB_EXTRACTdata extraction
XDSdata reduction
STARANISOdata scaling

Structure Validation

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Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United States1R15GM110641-01A1

Revision History  (Full details and data files)

  • Version 1.0: 2021-05-19
    Type: Initial release
  • Version 1.1: 2021-07-28
    Changes: Database references
  • Version 1.2: 2023-10-18
    Changes: Data collection, Database references, Refinement description