RNA polymerase I structure and transcription regulation

@article{Engel2013RNAPI,
  title={RNA polymerase I structure and transcription regulation},
  author={Christoph Engel and Sarah Sainsbury and Alan C. M. Cheung and Dirk Kostrewa and Patrick Cramer},
  journal={Nature},
  year={2013},
  volume={502},
  pages={650-655}
}
Transcription of ribosomal RNA by RNA polymerase (Pol) I initiates ribosome biogenesis and regulates eukaryotic cell growth. The crystal structure of Pol I from the yeast Saccharomyces cerevisiae at 2.8 Å resolution reveals all 14 subunits of the 590-kilodalton enzyme, and shows differences to Pol II. An ‘expander’ element occupies the DNA template site and stabilizes an expanded active centre cleft with an unwound bridge helix. A ‘connector’ element invades the cleft of an adjacent polymerase… 

Structure of RNA polymerase I transcribing ribosomal DNA genes

The structures of active transcribing Pol I from yeast solved by two different cryo-electron microscopy approaches suggest a model for the regulation of transcription elongation in which contracted and expanded polymerase conformations are associated with active and inactive states, respectively.

Structural Basis of RNA Polymerase I Transcription Initiation

Structural mechanism of ATP-independent transcription initiation by RNA polymerase I

Comparison of the three states in this study with the Pol II system suggests that a ratchet motion of the Core Factor-DNA sub-complex at upstream facilitates promoter melting in an ATP-independent manner, distinct from a DNA translocase actively threading the downstream DNA in thePol II PIC.

Conserved architecture of the core RNA polymerase II initiation complex.

The domain architecture of the yeast core pol II initiation complex during transcription initiation is derived and it is revealed that the TFIIF Tfg2 winged helix domain swings over promoter DNA.

Structure of an inactive RNA polymerase II dimer

Cryo-electron microscopy (cryo-EM) structure of a mammalian Pol II dimer is presented and reveals that one Pol II copy uses its RPB4-RPB7 stalk to penetrate the active centre cleft of the other copy, and vice versa, giving rise to a molecular handshake.

Structural insights into transcription initiation by yeast RNA polymerase I

The results show that although general features of eukaryotic transcription initiation are conserved, Pol I and Pol II use them differently in their respective transcription initiation complexes.

Structural basis of RNA polymerase I pre-initiation complex formation and promoter melting

The authors present the cryo-EM structure of a trapped early intermediate stage of promoter-recruited Pol I, which reveals the interactions of the basal rDNA transcription machinery with the native promoter, and discusses the mechanistic implications.

Structural basis of RNA polymerase I pre-initiation complex formation and promoter melting.

The authors present the cryo-EM structure of a trapped early intermediate stage of promoter-recruited Pol I, which reveals the interactions of the basal rDNA transcription machinery with the native promoter, and discusses the mechanistic implications.

Structural biology: Pivotal findings for a transcription machine

The basic architecture of Pol I resembles those of Pol II and Pol III, but its DNA-binding cleft adopts a wider conformation than seen in the other RNA polymerases, and other unique features also provide insights into the functional roles of its components.
...

References

SHOWING 1-10 OF 128 REFERENCES

Architecture of initiation-competent 12-subunit RNA polymerase II

A model of the complete Pol II is derived by fitting structures of the core and Rpb4/7 to a 4.2-Å crystallographic electron density map and finding that the wedge allosterically prevents entry of the promoter DNA duplex into the active center cleft and induces in two switch regions a conformation poised for template-strand binding.

Crystal structure of RNA polymerase I

The crystal structure of yeast Pol I, a 14-subunit complex with a total mass of 590 kDa, is obtained at 3.0 Å resolution, revealing intrinsic modules that only bind transiently in other RNA polymerases.

Structural basis of RNA polymerase II backtracking, arrest and reactivation

The structural basis of Pol II backtracking, arrest and reactivation is established, and a framework for analysing gene regulation during transcription elongation is provided.

Conformational flexibility of RNA polymerase III during transcriptional elongation

The transcribing Pol III enzyme structure not only shows the complete incoming DNA duplex, but also reveals the exit path of newly synthesized RNA, which likely increases processivity and provides structural insights into the conformational switch between Pol III‐mediated initiation and elongation.

RNA polymerase III subunit architecture and implications for open promoter complex formation

These results complete the subunit architecture of Pol III and indicate that all TFIIE-related components of eukaryotic and archaeal transcription systems adopt an evolutionarily conserved location in the upper part of the cleft that supports their functions in open promoter complex formation and stabilization.

Resolution of RNA Polymerase l into Dimers and Monomers and Their Function in Transcription

A model in which dimeric inactive pol I is converted into an active monomeric form that might be associated with other transcription factors to maintain a stable initiation competent complex is suggested.

Structure and function of the initially transcribing RNA polymerase II–TFIIB complex

The general transcription factor (TF) IIB is required for RNA polymerase (Pol) II initiation and extends with its B-reader element into the Pol II active centre cleft. Low-resolution structures of
...