Crystal structure of a MarR family transcriptional regulator protein

Abstract

The multiple antibiotic resistance regulator (MarR) family of transcription factor proteins form a large group of multitasking bio-molecules in pathogenic Escherichia coli (E. coli). HosA is one of these MarR transcription factors reported in dozens of pathogenic E. coli with highly conserved sequence profiles. The HosA from the enteropathogenic E. coli O127:H6 (strain E2348/69), a predominantly monomeric protein, was overexpressed in E. coli and purified. The HosA protein crystals were obtained in microbatch under oil method at 4{degrees} C. The X-rays of the diffracted spots were extended to 2.21 [A] resolution. The crystal belongs to the space group P4322, with unit-cell parameters a = 67.16 [A], b = 67.16 [A], c = 95.66 [A] and = {beta} = {gamma} = 90{degrees}. In the asymmetric unit, monomeric HosA protein was crystallized and confirmed with the Matthew coefficient analysis (3.48 [A]3 Da-1). The monomeric structure is compared with previously solved structures of other homologous transcription factors. This confirmed the winged loop at the DNA binding region of the HosA protein.