2ahq: Difference between revisions

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==Overview==

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.

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.

==About this Structure==

Line 14:

[[Category: Single protein]]

[[Category: Doucleff, M.]]

[[Category: Malak, L.T.]]

[[Category: Malak, L T.]]

[[Category: Pelton, J.G.]]

[[Category: Pelton, J G.]]

[[Category: Wemmer, D.E.]]

[[Category: Wemmer, D E.]]

[[Category: rna polymerase]]

[[Category: sigma factors]]

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[[Category: transcription]]

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@@ Line 4: / Line 4: @@
 ==Overview==
-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.
+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.
 ==About this Structure==
@@ Line 14: / Line 14: @@
 [[Category: Single protein]]
 [[Category: Doucleff, M.]]
-[[Category: Malak, L.T.]]
+[[Category: Malak, L T.]]
-[[Category: Pelton, J.G.]]
+[[Category: Pelton, J G.]]
-[[Category: Wemmer, D.E.]]
+[[Category: Wemmer, D E.]]
 [[Category: rna polymerase]]
 [[Category: sigma factors]]
@@ Line 23: / Line 23: @@
 [[Category: transcription]]
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Tue Jan 29 18:02:25 2008''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:27:32 2008''