1exi
From Proteopedia
|
CRYSTAL STRUCTURE OF TRANSCRIPTION ACTIVATOR BMRR, FROM B. SUBTILIS, BOUND TO 21 BASE PAIR BMR OPERATOR AND TPSB
Overview
The efflux of chemically diverse drugs by multidrug transporters that span, the membrane is one mechanism of multidrug resistance in bacteria. The, concentrations of many of these transporters are controlled by, transcription regulators, such as BmrR in Bacillus subtilis, EmrR in, Escherichia coli and QacR in Staphylococcus aureus. These proteins promote, transporter gene expression when they bind toxic compounds. BmrR activates, transcription of the multidrug transporter gene, bmr, in response to, cellular invasion by certain lipophilic cationic compounds (drugs). BmrR, belongs to the MerR family, which regulates response to stress such as, exposure to toxic compounds or oxygen radicals in bacteria. MerR proteins, have homologous amino-terminal DNA-binding domains but different, carboxy-terminal domains, which enable them to bind specific 'coactivator', molecules. When bound to coactivator, MerR proteins upregulate, transcription by reconfiguring the 19-base-pair spacer found between the, -35 and -10 promoter elements to allow productive interaction with RNA, polymerase. Here we report the 3.0 A resolution structure of BmrR in, complex with the drug tetraphenylphosphonium (TPP) and a 22-base-pair, oligodeoxynucleotide encompassing the bmr promoter. The structure reveals, an unexpected mechanism for transcription activation that involves, localized base-pair breaking, and base sliding and realignment of the -35, and -10 operator elements.
About this Structure
1EXI is a Single protein structure of sequence from Bacillus subtilis with ZN and 118 as ligands. Full crystallographic information is available from OCA.
Reference
Crystal structure of the transcription activator BmrR bound to DNA and a drug., Heldwein EE, Brennan RG, Nature. 2001 Jan 18;409(6818):378-82. PMID:11201751
Page seeded by OCA on Tue Nov 20 14:24:13 2007
