4X0E

Structure of M. tuberculosis nicotinate mono nucleotide adenylyltransferase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.41 Å
  • R-Value Free: 0.257 
  • R-Value Work: 0.221 
  • R-Value Observed: 0.223 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Mycobacterial nicotinate mononucleotide adenylyltransferase: structure, mechanism, and implications for drug discovery.

Rodionova, I.A.Zuccola, H.J.Sorci, L.Aleshin, A.E.Kazanov, M.D.Ma, C.T.Sergienko, E.Rubin, E.J.Locher, C.P.Osterman, A.L.

(2015) J Biol Chem 290: 7693-7706

  • DOI: 10.1074/jbc.M114.628016
  • Structures With Same Primary Citation

  • PubMed Abstract: 
  • Nicotinate mononucleotide adenylyltransferase NadD is an essential enzyme in the biosynthesis of the NAD cofactor, which has been implicated as a target for developing new antimycobacterial therapies. Here we report the crystal structure of Mycobacte ...

    Nicotinate mononucleotide adenylyltransferase NadD is an essential enzyme in the biosynthesis of the NAD cofactor, which has been implicated as a target for developing new antimycobacterial therapies. Here we report the crystal structure of Mycobacterium tuberculosis NadD (MtNadD) at a resolution of 2.4 Å. A remarkable new feature of the MtNadD structure, compared with other members of this enzyme family, is a 310 helix that locks the active site in an over-closed conformation. As a result, MtNadD is rendered inactive as it is topologically incompatible with substrate binding and catalysis. Directed mutagenesis was also used to further dissect the structural elements that contribute to the interactions of the two MtNadD substrates, i.e. ATP and nicotinic acid mononucleotide (NaMN). For inhibitory profiling of partially active mutants and wild type MtNadD, we used a small molecule inhibitor of MtNadD with moderate affinity (Ki ∼ 25 μM) and antimycobacterial activity (MIC80) ∼ 40-80 μM). This analysis revealed interferences with some of the residues in the NaMN binding subsite consistent with the competitive inhibition observed for the NaMN substrate (but not ATP). A detailed steady-state kinetic analysis of MtNadD suggests that ATP must first bind to allow efficient NaMN binding and catalysis. This sequential mechanism is consistent with the requirement of transition to catalytically competent (open) conformation hypothesized from structural modeling. A possible physiological significance of this mechanism is to enable the down-regulation of NAD synthesis under ATP-limiting dormancy conditions. These findings point to a possible new strategy for designing inhibitors that lock the enzyme in the inactive over-closed conformation.


    Organizational Affiliation

    From the Sanford-Burnham Medical Research Institute, La Jolla, California 92037, osterman@sanfordburnham.org.



Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Probable nicotinate-nucleotide adenylyltransferaseA, B219Mycobacterium tuberculosis H37RvMutation(s): 0 
Gene Names: nadDRv2421cMTCY428.26
EC: 2.7.7.18
Find proteins for P9WJJ5 (Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv))
Explore P9WJJ5 
Go to UniProtKB:  P9WJJ5
Protein Feature View
 ( Mouse scroll to zoom / Hold left click to move )
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
MES
Query on MES

Download CCD File 
B
2-(N-MORPHOLINO)-ETHANESULFONIC ACID
C6 H13 N O4 S
SXGZJKUKBWWHRA-UHFFFAOYSA-N
 Ligand Interaction
SO4
Query on SO4

Download CCD File 
B
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.41 Å
  • R-Value Free: 0.257 
  • R-Value Work: 0.221 
  • R-Value Observed: 0.223 
  • Space Group: P 31 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 67.65α = 90
b = 67.65β = 90
c = 187.366γ = 120
Software Package:
Software NamePurpose
REFMACrefinement
PROCESSdata reduction
PROCESSdata scaling
PHASERphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2015-01-28
    Type: Initial release
  • Version 1.1: 2016-06-01
    Changes: Data collection
  • Version 1.2: 2017-12-13
    Changes: Database references, Derived calculations