Publication details
Assembly of the Xrn2/Rat1–Rai1–Rtt103 termination complexes in mesophilic and thermophilic organisms
| Authors | |
|---|---|
| Year of publication | 2024 |
| Type | Article in Periodical |
| Magazine / Source | Structure |
| MU Faculty or unit | |
| Citation | |
| web | https://www.sciencedirect.com/science/article/pii/S0969212624005008?ref=pdf_download&fr=RR-2&rr=8f0ce12baef9f976 |
| Doi | http://dx.doi.org/10.1016/j.str.2024.11.010 |
| Keywords | exoribonuclease Xrn2; Rat1; pomyerase RNAPII; CTD; Rtt103; structure |
| Description | The 50–30 exoribonuclease Xrn2, known as Rat1 in yeasts, terminates mRNA transcription by RNA polymeraseII (RNAPII). In the torpedo model of termination, the activity of Xrn2/Rat1 is enhanced by Rai1, which is recruited to the termination site by Rtt103, an adaptor protein binding to the RNAPII C-terminal domain(CTD). The overall architecture of the Xrn2/Rat1-Rai1-Rtt103 complex remains unknown. We combined structural biology methods to characterize the torpedo complex from Saccharomyces cerevisiae and Chaetomium thermophilum. Comparison of the structures from these organisms revealed a conserved protein core fold of the subunits, but significant variability in their interaction interfaces. We found that in the mesophile, Rtt103 utilizes an unstructured region to augment a Rai1 b-sheet, while in the thermophile Rtt103 binds to a C-terminal helix of Rai1 via its CTD-interacting domain with an a-helical fold. These different torpedo complex assemblies reflect adaptations to the environment and impact complex recruitment to RNAPII. |
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