Assembly of proteins and 5S rRNA to transcripts of the major structural domains of 23S rRNA
Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
The six major structural domains of 23 S rRNA from Escherichia coli, and all combinations thereof, were synthesized as separate T7 transcripts and reconstituted with total 50 S subunit proteins. Analysis by one and two-dimensional gel electrophoresis demonstrated the presence of at least one primary binding protein associated with each RNA domain and additional proteins assembled to domains I, II, V and VI. For all the combinations of two to five domains, enhanced assembly yields and/or new proteins were observed primarily to those transcripts containing either domains I+II or domains V+VI. This indicates that there are two major protein assembly centres located at the ends of the 23 S rRNA, which is consistent with an earlier view that in vitro protein assembly nucleates around proteins L24 and L3. Although similar protein assembly patterns were observed over a range of temperature and magnesium concentrations, protein L2 assembled strongly with domains II and IV at 4-8 mM Mg2+ (the first step of the two-step reconstitution procedure) and with domain IV alone at higher Mg2+ concentrations (the second step). It is proposed that this change in protein-RNA binding provides a basis for the two-step reconstitution in vitro. A chemical footprinting approach was employed on the reconstituted protein-domain complexes to localize a putative L4 binding region within domain I to a region that is partially co-structural with the site on the L4-mRNA where L4 binds and inhibits its own translation. A similar approach was used to map the putative binding regions on domain V of protein L9 and the 5 S RNA-L5-L18 complex.
Originalsprog | Engelsk |
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Tidsskrift | Journal of Molecular Biology |
Vol/bind | 284 |
Udgave nummer | 2 |
Sider (fra-til) | 227-240 |
Antal sider | 13 |
ISSN | 0022-2836 |
DOI | |
Status | Udgivet - 1 nov. 1998 |
Bibliografisk note
Copyright 1998 Academic Press.
ID: 217315