Crystallization
and preliminary X-ray crystallographic analysis of the complexes:
Shikimate Kinase:ADP:shikimate and Shikimate Kinase:ADP:Mg2+ from Mycobacterium tuberculosis
Faim, LM1; Dias, MVB1; Vasconcelos, IB2; Oliveira, JS2; Basso, LA2; Santos, DS2; Azevedo Jr.,WF1,2
1 - IBILCE - UNESP - São José do Rio Preto SP; 2 - PUC - Porto Alegre - RS;
The
seven step shikimate pathway links the metabolism of carbohydrates to
the biosynthesis of aromatic amino acids and many aromatic secondary
metabolites. It provides excellent potential targets for antimicrobial
and agents because it is absent in animals but is essential in
bacteria. Shikimate kinase is the fifth enzyme in this pathway and it
catalyses the phosphorylation of the 3-hydroxyl group of shikimate
using ATP as a co-substrate. In this work, we present crystallization
and preliminary X-ray crystallographic analysis of shikimate kinase
from Mycobacterium tuberculosis (MtSK) in two complexes: MtSK:ADP:shikimate and MtSK:ADP:Mg2+. For
crystallization of these two complexes were used the hanging drop vapor
diffusion and sparse matrix methods. X-ray diffraction data sets were
collect at wavelength of 1.427Ǻ using the Synchrotron Radiation Source.
The data were processed using the program Mosflm and Scala. The complex
MtSK:ADP:shikimate was crystallized in Tris–HCl, 17% of PEG 1500 and 0.5–0.7M of LiCl, while the complex MtSK:ADP:Mg2+ was crystallized in Tris–HCl, 25% of PEG 3350 and 0,1M of MgCl2. X-ray diffraction data were processed to resolution of 1.93Ǻ and 2.8Ǻ to MtSK:ADP:shikimate and to MtSK:ADP:Mg2+, respectively. The crystals of MtSK:ADP:shikimate are trigonal and belong to P3221 space group with unit cell dimensions of a=b=63.3 and c=91.6Å and present one molecule per asymmetric unit. The crystals of MtSK:ADP:Mg2+ are orthorhombic and belong to P212121 space
group with unit cell dimensions of a=60.62, b=62.20 and c=170.63Å and
present four molecules per asymmetric unit. The data sets present here
posses an Rsym below of 12.1% and completeness above of
96.9%. With these results we intend to determine the crystallographic
structure of MtSK for these two complexes and to verify the possible
conformational changes caused for Mg2+ and for shikimate molecule. Furthermore these data can be until in the development new drugs against infectious disease. Fapesp (processes 05/50446-9, 03/12472-2 and 01/07532-0).
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