5XE7

Crystal structure of Mycobacterium tuberculosis extracytoplasmic function sigma factor SigJ

Summary for 5XE7

• Entry DOI: 10.2210/pdb5xe7/pdb
• Descriptor: ECF RNA polymerase sigma factor SigJ (2 entities in total)
• Functional Keywords: rna polymerase subunit, ecf41 sigma factor, dna binding, snoal_2 domain, dna binding protein
• Biological source: Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv)
• Total number of polymer chains: 2
• Total formula weight: 67420.37

Authors

Goutam, K.,Gopal, B. (deposition date: 2017-04-01, release date: 2017-07-19, Last modification date: 2024-10-30)

Primary citation

Goutam, K.,Gupta, A.K.,Gopal, B.
The fused SnoaL_2 domain in the Mycobacterium tuberculosis sigma factor sigma J modulates promoter recognition
Nucleic Acids Res., 45:9760-9772, 2017

PubMed Abstract: Extra-cytoplasmic function (ECF) σ-factors are widespread in bacteria, linking environmental stimuli with changes in gene expression. These transcription factors span several phylogenetically distinct groups and are remarkably diverse in their activation and regulatory mechanisms. Here, we describe the structural and biochemical features of a Mycobacterium tuberculosis ECF factor σJ that suggests that the SnoaL_2 domain at the C-terminus can modulate the activity of this initiation factor in the absence of a cognate regulatory anti-σ factor. M. tuberculosis σJ can bind promoter DNA in vitro; this interaction is substantially impaired by the removal of the SnoaL_2 domain. This finding is consistent with assays to evaluate σJ-mediated gene expression. Structural similarity of the SnoaL_2 domain with epoxide hydrolases also suggests a novel functional role for this domain. The conserved sequence features between M. tuberculosis σJ and other members of the ECF41 family of σ-factors suggest that the regulatory mechanism involving the C-terminal SnoaL_2 domain is likely to be retained in this family of proteins. These studies suggest that the ECF41 family of σ-factors incorporate features of both-the σ70 family and bacterial one-component systems thereby providing a direct mechanism to implement environment-mediated transcription changes.

PubMed: 28934483
DOI: 10.1093/nar/gkx609

Experimental method

X-RAY DIFFRACTION (2.162 Å)