Doctoral theses
Current Record: 293 of 340
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Identifier |
uch.biology.phd//1997DIS158 |
Title |
Δομική και λειτουργική ανάλυση της κοινής υπομονάδας των RNA πολυμερασών Rpb8 |
Author
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Βουτσινά, Αλεξάνδρα
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Abstract |
Yeast nuclear RNA polymerases are organised around a core of four subunits related to the bacteria l core enzyme (ββ'α2), share five subunits and contain several en zyme-specific subunits. Rpb8 is one of the five common subunits (Rp b5,Rpb6, Rpb8, Rpb10α, Rpb10β) encoded by a single copy gene that is essential for viability. The structural and fuctional conservation of the Rpb8 homologue in human and the absence of such a homologue in A rchael RNA polymerase, characterizes the Rpb8 subunits as typical eu karyotic and implies its central role in transcription.However the percise role of tha Rpb8 subunit in eukaryotic transcription is stil l elusive.In the present work, the Shizosaccharomyces pombe cDNA homo logous to the RPB8 gene of Saccharomyces cerevisiae was isolated as a high copy supperssor of the gcn2 mutation.The rpb8 cDNA predicts a p rotein sequence of 125 amino acids.Alignement of the S.pombe rpb8 and S.cerevisiae Rpb8 (146 residues)subunit sequences revealed an extensi ve amount of similarity (42% identical and 60% similar aminoacids) between the two proteins.Despite this similarity,the S.pombe rpb8 su bunit was not able to complement the lethal phenotype of the correspo nding null allele in S.cerevisiae.It was demonstrated that the S.pom be rpb8 subunit competes the endogenous Rpb8 subunit for its proper function and overcomes the gcn2 defect by increasing constitutively t he translation of the GCN4 mRNA. Over expression of the rpb8 subunit enhanced further translation of the GCN4mRNA and resulted in slow growth and cold sensitive phenotypes in gcn2 as well (περικοπή περίληψης)
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Language |
Greek |
Issue date |
1997-05-29 |
Collection
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School/Department--School of Sciences and Engineering--Department of Biology--Doctoral theses
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Type of Work--Doctoral theses
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Permanent Link |
https://elocus.lib.uoc.gr//dlib/8/0/d/metadata-dlib-1997DIS158.tkl
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Views |
234 |
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