Crystallization and preliminary X-ray diffraction analysis of biotin acetyl-CoA carboxylase ligase (BirA) from Mycobacterium tuberculosis.
The gene encoding biotin acetyl-CoA carboxylase ligase (BirA) from Mycobacterium tuberculosis was cloned and expressed in Escherichia coli with a C-terminal Strep-tag. PEG 4000 as well as PEG 8000 were used as precipitants at pH 7.5 to crystallize the protein using the vapour-diffusion technique. X-ray characterization of crystals at room temperature indicated that the crystals belonged to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 79.7, b = 62.8, c = 105.8 A. Assuming the presence of two BirA molecules in the asymmetric unit, the solvent content of the crystals was 44% (V(M) = 2.2 A(3) Da(-1)). When transferred to a cryoprotectant, crystals grown in the same drop exhibited a difference in one unit-cell parameter, with a = 60.1, b = 64.0, c = 103.6 A, but belonged to the same P2(1)2(1)2(1) space group. These crystals, with two molecules of BirA present per asymmetric unit, appeared to have a very low solvent content of 28% (V(M) = 1.7 A(3) Da(-1)).
Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi 110 021, India.
Vibha
V
Gupta
Rakesh K
RK
Gupta
Garima
G
Khare
Avadhesha
A
Surolia
Dinakar M
DM
Salunke
Anil K
AK
Tyagi
D019731:Carbon-Nitrogen Ligases / Q000737:chemistry* / Q000235:genetics; D003001:Cloning, Molecular; D003460:Crystallization; D004926:Escherichia coli / Q000235:genetics; D009169:Mycobacterium tuberculosis / Q000201:enzymology*; D013696:Temperature; D014961:X-Ray Diffraction
D019731:Carbon-Nitrogen Ligases; C027739:biotin-(acetyl-CoA carboxylase)synthetase