2ppb: Difference between revisions

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==Overview==

The mechanism of substrate loading in multisubunit RNA polymerase is, crucial for understanding the general principles of transcription yet, remains hotly debated. Here we report the 3.0-A resolution structures of, the Thermus thermophilus elongation complex (EC) with a non-hydrolysable, substrate analogue, adenosine-5'-[(alpha,beta)-methyleno]-triphosphate, (AMPcPP), and with AMPcPP plus the inhibitor streptolydigin. In the, EC/AMPcPP structure, the substrate binds to the active ('insertion') site, closed through refolding of the trigger loop (TL) into two alpha-helices., In contrast, the EC/AMPcPP/streptolydigin structure reveals an inactive, ('preinsertion') substrate configuration stabilized by, streptolydigin-induced displacement of the TL. Our structural and, biochemical data suggest that refolding of the TL is vital for catalysis, and have three main implications. First, despite differences in the, details, the two-step preinsertion/insertion mechanism of substrate, loading may be universal for all RNA polymerases. Second, freezing of the, preinsertion state is an attractive target for the design of novel, antibiotics. Last, the TL emerges as a prominent target whose refolding, can be modulated by regulatory factors.

The mechanism of substrate loading in multisubunit RNA polymerase is crucial for understanding the general principles of transcription yet remains hotly debated. Here we report the 3.0-A resolution structures of the Thermus thermophilus elongation complex (EC) with a non-hydrolysable substrate analogue, adenosine-5'-[(alpha,beta)-methyleno]-triphosphate (AMPcPP), and with AMPcPP plus the inhibitor streptolydigin. In the EC/AMPcPP structure, the substrate binds to the active ('insertion') site closed through refolding of the trigger loop (TL) into two alpha-helices. In contrast, the EC/AMPcPP/streptolydigin structure reveals an inactive ('preinsertion') substrate configuration stabilized by streptolydigin-induced displacement of the TL. Our structural and biochemical data suggest that refolding of the TL is vital for catalysis and have three main implications. First, despite differences in the details, the two-step preinsertion/insertion mechanism of substrate loading may be universal for all RNA polymerases. Second, freezing of the preinsertion state is an attractive target for the design of novel antibiotics. Last, the TL emerges as a prominent target whose refolding can be modulated by regulatory factors.

==About this Structure==

Line 10:

==Reference==

Structural basis for substrate loading in bacterial RNA polymerase., Vassylyev DG, Vassylyeva MN, Zhang J, Palangat M, Artsimovitch I, Landick R, Nature. 2007 Jun 20;. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17581591 17581591]

Structural basis for substrate loading in bacterial RNA polymerase., Vassylyev DG, Vassylyeva MN, Zhang J, Palangat M, Artsimovitch I, Landick R, Nature. 2007 Jul 12;448(7150):163-8. Epub 2007 Jun 20. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17581591 17581591]

[[Category: DNA-directed RNA polymerase]]

[[Category: Protein complex]]

Line 16:

[[Category: Artsimovitch, I.]]

[[Category: Landick, R.]]

[[Category: Vassylyev, D.G.]]

[[Category: Vassylyev, D G.]]

[[Category: Vassylyeva, M.N.]]

[[Category: Vassylyeva, M N.]]

[[Category: APC]]

[[Category: MG]]

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[[Category: template dna]]

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@@ Line 4: / Line 4: @@
 ==Overview==
-The mechanism of substrate loading in multisubunit RNA polymerase is, crucial for understanding the general principles of transcription yet, remains hotly debated. Here we report the 3.0-A resolution structures of, the Thermus thermophilus elongation complex (EC) with a non-hydrolysable, substrate analogue, adenosine-5'-[(alpha,beta)-methyleno]-triphosphate, (AMPcPP), and with AMPcPP plus the inhibitor streptolydigin. In the, EC/AMPcPP structure, the substrate binds to the active ('insertion') site, closed through refolding of the trigger loop (TL) into two alpha-helices., In contrast, the EC/AMPcPP/streptolydigin structure reveals an inactive, ('preinsertion') substrate configuration stabilized by, streptolydigin-induced displacement of the TL. Our structural and, biochemical data suggest that refolding of the TL is vital for catalysis, and have three main implications. First, despite differences in the, details, the two-step preinsertion/insertion mechanism of substrate, loading may be universal for all RNA polymerases. Second, freezing of the, preinsertion state is an attractive target for the design of novel, antibiotics. Last, the TL emerges as a prominent target whose refolding, can be modulated by regulatory factors.
+The mechanism of substrate loading in multisubunit RNA polymerase is crucial for understanding the general principles of transcription yet remains hotly debated. Here we report the 3.0-A resolution structures of the Thermus thermophilus elongation complex (EC) with a non-hydrolysable substrate analogue, adenosine-5'-[(alpha,beta)-methyleno]-triphosphate (AMPcPP), and with AMPcPP plus the inhibitor streptolydigin. In the EC/AMPcPP structure, the substrate binds to the active ('insertion') site closed through refolding of the trigger loop (TL) into two alpha-helices. In contrast, the EC/AMPcPP/streptolydigin structure reveals an inactive ('preinsertion') substrate configuration stabilized by streptolydigin-induced displacement of the TL. Our structural and biochemical data suggest that refolding of the TL is vital for catalysis and have three main implications. First, despite differences in the details, the two-step preinsertion/insertion mechanism of substrate loading may be universal for all RNA polymerases. Second, freezing of the preinsertion state is an attractive target for the design of novel antibiotics. Last, the TL emerges as a prominent target whose refolding can be modulated by regulatory factors.
 ==About this Structure==
@@ Line 10: / Line 10: @@
 ==Reference==
-Structural basis for substrate loading in bacterial RNA polymerase., Vassylyev DG, Vassylyeva MN, Zhang J, Palangat M, Artsimovitch I, Landick R, Nature. 2007 Jun 20;. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17581591 17581591]
+Structural basis for substrate loading in bacterial RNA polymerase., Vassylyev DG, Vassylyeva MN, Zhang J, Palangat M, Artsimovitch I, Landick R, Nature. 2007 Jul 12;448(7150):163-8. Epub 2007 Jun 20. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17581591 17581591]
 [[Category: DNA-directed RNA polymerase]]
 [[Category: Protein complex]]
@@ Line 16: / Line 16: @@
 [[Category: Artsimovitch, I.]]
 [[Category: Landick, R.]]
-[[Category: Vassylyev, D.G.]]
+[[Category: Vassylyev, D G.]]
-[[Category: Vassylyeva, M.N.]]
+[[Category: Vassylyeva, M N.]]
 [[Category: APC]]
 [[Category: MG]]
@@ Line 30: / Line 30: @@
 [[Category: template dna]]
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Wed Jan 23 14:14:38 2008''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 18:31:45 2008''