| dc.contributor.advisor | Ficner, Ralf Prof. Dr. | |
| dc.contributor.author | Christian, Henning | |
| dc.date.accessioned | 2013-11-20T10:41:46Z | |
| dc.date.available | 2013-11-20T10:41:46Z | |
| dc.date.issued | 2013-11-20 | |
| dc.identifier.uri | http://hdl.handle.net/11858/00-1735-0000-0001-BC73-A | |
| dc.identifier.uri | http://dx.doi.org/10.53846/goediss-4180 | |
| dc.identifier.uri | http://dx.doi.org/10.53846/goediss-4180 | |
| dc.language.iso | eng | de |
| dc.rights.uri | http://creativecommons.org/licenses/by-nc-nd/3.0/ | |
| dc.subject.ddc | 572 | de |
| dc.title | Insights into the activation of the spliceosomal helicase Prp43 | de |
| dc.type | doctoralThesis | de |
| dc.contributor.referee | Ficner, Ralf Prof. Dr. | |
| dc.date.examination | 2013-04-09 | |
| dc.description.abstracteng | The excision of non-coding sequences that are present in the pre-mRNA is a
hallmark of eukaryotic cells. This process is termed as splicing and is catalysed
by the spliceosome, a single-turnover enzyme which consists of five Uridine-rich
smal nuclear snRNAs (UsnRNAs) and more than 100 associated proteins. For
each intron to be excised, the spliceosome is assembled, catalyses the two-step
splicing reaction and is disassembled afterwards.
The dynamics of the spliceosome is controlled by at least eight conserved
DExD/H-box ATPases which promote the transitions between the different steps
of the splicing cycle and are also implicated in the quality control. Hence, the
activity of these molecular motors has to be highly and precisely regulated.
Subsequent to the release of the mature mRNA, the DEAH-box ATPase Prp43
catalyses the disassembly of the intron-lariat spliceosome. During this process,
Prp43 is activated by the heterodimer Ntr1/Ntr2, which form together the ternary
NTR complex. The binding of the N-terminal part of Ntr1 which contains a
G-patch motif stimulates the helicase activity of Prp43. Recently, the crystal
structure analysis of Prp43 from yeast in complex with ADP has revealed that
besides the helicase core, Prp43 contains an N-terminal extension and a winged
helix, a ratchet and an OB-fold domain. As the structure represents Prp43 in its
post-catalytic state, it provides no information about the conformational changes
that lead to the activation upon binding of Ntr1.
Here it is shown that the fragment Ntr1(51-110) is both required and sufficient
for the activation of Prp43 and thereby stimulates its helicase as well as its ATPase
activity. Furthermore, evidence is provided that the interaction with Ntr1 is
mediated by the OB-fold domain of Prp43 and that the ratchet domain of Prp43
is involved in RNA binding. The results presented here suggest that the G-patch
motif of Ntr1 is intrinsically unstructured and directly implicated in RNA binding.
Additionally, Prp43 from the thermophile eukaryote Chaetomium thermophilum
is biochemically and structurally characterised. In summary, these results provide
new insights into the activation of Prp43. | de |
| dc.contributor.coReferee | Lührmann, Reinhard Prof. Dr. | |
| dc.subject.eng | helicase | de |
| dc.identifier.urn | urn:nbn:de:gbv:7-11858/00-1735-0000-0001-BC73-A-8 | |
| dc.affiliation.institute | Göttinger Graduiertenschule für Neurowissenschaften, Biophysik und molekulare Biowissenschaften (GGNB) | de |
| dc.subject.gokfull | Biologie (PPN619462639) | de |
| dc.identifier.ppn | 772017476 | |