2AHQ

Solution Structure of the C-terminal RpoN Domain of Sigma-54 from Aquifex aeolicus

Summary for 2AHQ

• Entry DOI: 10.2210/pdb2ahq/pdb
• NMR Information: BMRB: 6816
• Descriptor: RNA polymerase sigma factor RpoN (1 entity in total)
• Functional Keywords: sigma-54, sigma factors, solution structure, transcription, rna polymerase
• Biological source: Aquifex aeolicus
• Total number of polymer chains: 1
• Total formula weight: 8966.38

Authors

Doucleff, M.,Malak, L.T.,Pelton, J.G.,Wemmer, D.E. (deposition date: 2005-07-28, release date: 2005-10-11, Last modification date: 2024-05-22)

Primary citation

Doucleff, M.,Malak, L.T.,Pelton, J.G.,Wemmer, D.E.
The C-terminal RpoN domain of sigma54 forms an unpredicted helix-turn-helix motif similar to domains of sigma70.
J.Biol.Chem., 280:41530-41536, 2005

PubMed Abstract: The "sigma" subunit of prokaryotic RNA polymerase allows gene-specific transcription initiation. Two sigma families have been identified, sigma70 and sigma54, which use distinct mechanisms to initiate transcription and share no detectable sequence homology. Although the sigma70-type factors have been well characterized structurally by x-ray crystallography, no high resolution structural information is available for the sigma54-type factors. Here we present the NMR-derived structure of the C-terminal domain of sigma54 from Aquifex aeolicus. This domain (Thr-323 to Gly-389), which contains the highly conserved RpoN box sequence, consists of a poorly structured N-terminal tail followed by a three-helix bundle, which is surprisingly similar to domains of the sigma70-type proteins. Residues of the RpoN box, which have previously been shown to be critical for DNA binding, form the second helix of an unpredicted helix-turn-helix motif. The homology of this structure with other DNA-binding proteins, combined with previous biochemical data, suggests how the C-terminal domain of sigma54 binds to DNA.

PubMed: 16210314
DOI: 10.1074/jbc.M509010200

Experimental method

SOLUTION NMR