2M4V

Mycobacterium tuberculosis RNA polymerase binding protein A (RbpA) and its interactions with sigma factors

Summary for 2M4V

• Entry DOI: 10.2210/pdb2m4v/pdb
• NMR Information: BMRB: 19023
• Descriptor: Putative uncharacterized protein (1 entity in total)
• Functional Keywords: transcription
• Biological source: Mycobacterium tuberculosis
• Total number of polymer chains: 1
• Total formula weight: 9026.07

Authors

Bortoluzzi, A.,Muskett, F.W.,Waters, L.C.,Addis, P.W.,Rieck, B.,Munder, T.,Schleier, S.,Forti, F.,Ghisotti, D.,Carr, M.D.,O'Hare, H.M. (deposition date: 2013-02-11, release date: 2013-04-17, Last modification date: 2024-05-15)

Primary citation

Bortoluzzi, A.,Muskett, F.W.,Waters, L.C.,Addis, P.W.,Rieck, B.,Munder, T.,Schleier, S.,Forti, F.,Ghisotti, D.,Carr, M.D.,O'Hare, H.M.
Mycobacterium tuberculosis RNA polymerase-binding protein A (RbpA) and its interactions with sigma factors.
J.Biol.Chem., 288:14438-14450, 2013

PubMed Abstract: RNA polymerase-binding protein A (RbpA), encoded by Rv2050, is specific to the actinomycetes, where it is highly conserved. In the pathogen Mycobacterium tuberculosis, RbpA is essential for growth and survival. RbpA binds to the β subunit of the RNA polymerase where it activates transcription by unknown mechanisms, and it may also influence the response of M. tuberculosis to the current frontline anti-tuberculosis drug rifampicin. Here we report the solution structure of RbpA and identify the principle sigma factor σ(A) and the stress-induced σ(B) as interaction partners. The protein has a central ordered domain with a conserved hydrophobic surface that may be a potential protein interaction site. The N and C termini are highly dynamic and are involved in the interaction with the sigma factors. RbpA forms a tight complex with the N-terminal domain of σ(B) via its N- and C-terminal regions. The interaction with sigma factors may explain how RbpA stabilizes sigma subunit binding to the core RNA polymerase and thereby promotes initiation complex formation. RbpA could therefore influence the competition between principal and alternative sigma factors and hence the transcription profile of the cell.

PubMed: 23548911
DOI: 10.1074/jbc.M113.459883

Experimental method

SOLUTION NMR