2F6L

X-ray structure of Chorismate Mutase from Mycobacterium Tuberculosis


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.222 
  • R-Value Work: 0.182 

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This is version 1.3 of the entry. See complete history


Literature

Biochemical and structural characterization of the secreted chorismate mutase (Rv1885c) from Mycobacterium tuberculosis H37Rv: an *AroQ enzyme not regulated by the aromatic amino acids.

Kim, S.K.Reddy, S.K.Nelson, B.C.Vasquez, G.B.Davis, A.Howard, A.J.Patterson, S.Gilliland, G.L.Ladner, J.E.Reddy, P.T.

(2006) J Bacteriol 188: 8638-8648

  • DOI: 10.1128/JB.00441-06
  • Primary Citation of Related Structures:  
    2F6L

  • PubMed Abstract: 
  • The gene Rv1885c from the genome of Mycobacterium tuberculosis H37Rv encodes a monofunctional and secreted chorismate mutase (*MtCM) with a 33-amino-acid cleavable signal sequence; hence, it belongs to the *AroQ class of chorismate mutases. Consistent with the heterologously expressed *MtCM having periplasmic destination in Escherichia coli and the absence of a discrete periplasmic compartment in M ...

    The gene Rv1885c from the genome of Mycobacterium tuberculosis H37Rv encodes a monofunctional and secreted chorismate mutase (*MtCM) with a 33-amino-acid cleavable signal sequence; hence, it belongs to the *AroQ class of chorismate mutases. Consistent with the heterologously expressed *MtCM having periplasmic destination in Escherichia coli and the absence of a discrete periplasmic compartment in M. tuberculosis, we show here that *MtCM secretes into the culture filtrate of M. tuberculosis. *MtCM functions as a homodimer and exhibits a dimeric state of the protein at a concentration as low as 5 nM. *MtCM exhibits simple Michaelis-Menten kinetics with a Km of 0.5 +/- 0.05 mM and a k(cat) of 60 s(-1) per active site (at 37 degrees C and pH 7.5). The crystal structure of *MtCM has been determined at 1.7 A resolution (Protein Data Bank identifier 2F6L). The protein has an all alpha-helical structure, and the active site is formed within a single chain without any contribution from the second chain in the dimer. Analysis of the structure shows a novel fold topology for the protein with a topologically rearranged helix containing Arg134. We provide evidence by site-directed mutagenesis that the residues Arg49, Lys60, Arg72, Thr105, Glu109, and Arg134 constitute the catalytic site; the numbering of the residues includes the signal sequence. Our investigation on the effect of phenylalanine, tyrosine, and tryptophan on *MtCM shows that *MtCM is not regulated by the aromatic amino acids. Consistent with this observation, the X-ray structure of *MtCM does not have an allosteric regulatory site.


    Organizational Affiliation

    Biochemical Science Division, National Institute of Standards and Technology, Mail stop 831.2, Bldg. 227, Room B244, Gaithersburg, MD 20899, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Chorismate mutaseA, B166Mycobacterium tuberculosis H37RvMutation(s): 0 
Gene Names: Rv1885c
EC: 5.4.99.5
UniProt
Find proteins for P9WIB9 (Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv))
Explore P9WIB9 
Go to UniProtKB:  P9WIB9
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.222 
  • R-Value Work: 0.182 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 42.89α = 90
b = 72.93β = 103.85
c = 62.06γ = 90
Software Package:
Software NamePurpose
PHASERphasing
REFMACrefinement
PDB_EXTRACTdata extraction
X-GENdata reduction
X-GENdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2005-12-13
    Type: Initial release
  • Version 1.1: 2008-05-01
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Source and taxonomy, Version format compliance
  • Version 1.3: 2017-10-18
    Changes: Refinement description