RsaM: a transcriptional regulator of Burkholderia spp. with novel fold
- Midwest Center for Structural Genomics, Argonne National Laboratory, IL USA; Structural Biology Center, Biosciences Division, Argonne National Laboratory, IL USA
- Midwest Center for Structural Genomics, Argonne National Laboratory, IL USA
- Department of Microbiology, Cornell University, Ithaca NY USA
- Midwest Center for Structural Genomics, Argonne National Laboratory, IL USA; Structural Biology Center, Biosciences Division, Argonne National Laboratory, IL USA; Department of Biochemistry and Molecular Biology, University of Chicago, IL USA
Burkholderia cepacia complex (Bcc) is a set of closely related bacterial species that are notorious pathogens of cystic fibrosis patients, responsible for life-threatening lung infections. Expression of several virulence factors of Bcc is controlled by a mechanism known as quorum sensing (QS). QS is a means of bacterial communication used to coordinate gene expression in a cell-density-dependent manner. The system involves the production of diffusible signaling molecules (N-acyl-L-homoserine lactones, AHLs), that bind to cognate transcriptional regulators and influence their ability to regulate gene expression. One such system that is highly conserved in Bcc consists of CepI and CepR. CepI is AHL synthase, while CepR is an AHL-dependent transcription factor. In most members of the Bcc group, the cepI and cepR genes are divergently transcribed and separated by additional genes. One of them, bcam1869, encodes the BcRsaM protein, which was recently postulated to modulate the abundance or activity of CepI or CepR. Here we show the crystal structure of BcRsaM from B. cenocepacia J2315. It is a single-domain protein with unique topology and presents a novel fold. The protein is a dimer in the crystal and in solution. This regulator has no known DNA binding motifs and direct binding of BcRsaM to the cepI promoter could not be detected in in vitro assays. Therefore, we propose that the modulatory action of RsaM might result from interactions with other components of the QS machinery rather than from direct association with the DNA promoter.
- Research Organization:
- Argonne National Laboratory (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- National Institutes of Health (NIH); USDOE Office of Science - Office of Biological and Environmental Research
- DOE Contract Number:
- AC02-06CH11357
- OSTI ID:
- 1396289
- Journal Information:
- Federation of European Biochemical Societies (FEBS) Journal, Vol. 281, Issue 18; ISSN 1742-464X
- Publisher:
- Federation of European Biochemical Societies
- Country of Publication:
- United States
- Language:
- English
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