Crystallization and preliminary X-ray diffraction studies of the transcriptional repressor PaaX, the main regulator of the phenylacetic acid degradation pathway in Escherichia coli W

• Published in: Acta crystallographica. Section F, Structural biology and crystallization communications Structural biology and crystallization communications, 2011-10, Vol.67 (10), p.1278-1280
• Main Authors: Rojas-Altuve, Alzoray, Carrasco-López, César, Hernández-Rocamora, Víctor M., Sanz, Jesús M., Hermoso, Juan A.
• Format: Article
• Language: English
• Subjects: Crystallization; Crystallization Communications; Crystallography, X-Ray; Escherichia coli; Escherichia coli - chemistry; Escherichia coli Proteins - chemistry; Escherichia coli W; PaaX; phenylacetic acid degradation pathway; Repressor Proteins - chemistry
• ISSN: 1744-3091; 1744-3091; 2053-230X
• DOI: 10.1107/S1744309111029873

PaaX is the main regulator of the phenylacetic acid aerobic degradation pathway in bacteria and acts as a transcriptional repressor in the absence of its inducer phenylacetyl‐coenzyme A. The natural presence and the recent accumulation of a variety of highly toxic aromatic compounds owing to human pollution has created considerable interest in the study of degradation pathways in bacteria, the most important microorganisms capable of recycling these compounds, in order to design and apply novel bioremediation strategies. PaaX from Escherichia coli W was cloned, overexpressed, purified and crystallized using the sitting‐drop vapour‐diffusion method at 291 K. Crystals grew from a mixture of 0.9 M Li2SO4 and 0.5 M sodium citrate pH 5.8. These crystals, which belonged to the monoclinic space group C2 with unit‐cell parameters a = 167.88, b = 106.23, c = 85.87 Å, β = 108.33°, allowed the collection of an X‐ray data set to 2.3 Å resolution.