Variable region V1 of Saccharomyces cerevisiae 18S rRNA participates in biogenesis and function of the small ribosomal subunit.
Chromosoma
; 105(7-8): 523-31, 1997 Jun.
Article
em En
| MEDLINE
| ID: mdl-9211980
ABSTRACT
The role of helix 6, which forms the major portion of the most 5'-located expansion segment of Saccharomyces cerevisiae 18S rRNA, was studied by in vivo mutational analysis. Mutations that increased the size of the helical part and/or the loop, even to a relatively small extent, abolished 18S rRNA formation almost completely. Concomitantly, 35S pre-rRNA and an abnormal 23S precursor species accumulated. rDNA units containing these mutations did not support cell growth. A deletion removing helix 6 almost completely, on the other hand, had a much less severe effect on the formation of 18S rRNA, and cells expressing only the mutant rRNA remained able to grow, albeit at a much reduced rate. Disruption of the apical A.U base pair by a single point mutation did not cause a noticeable reduction in the level of 18S rRNA but did result in a twofold lower growth rate of the cells. This effect could not be reversed by introduction of a second point mutation that restores base pairing. We conclude that both the primary and the secondary structure of helix 6 play an important role in the formation and the biological function of the 40S subunit.
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Base de dados:
MEDLINE
Assunto principal:
Saccharomyces cerevisiae
/
Variação Genética
/
RNA Ribossômico
/
RNA Ribossômico 18S
Idioma:
En
Ano de publicação:
1997
Tipo de documento:
Article