Ribosome structure. Localization of 7-methylguanosine in the small subunits of Escherichia coli and chloroplast ribosomes by immunoelectron microscopy.
J Biol Chem
; 257(16): 9822-9, 1982 Aug 25.
Article
em En
| MEDLINE
| ID: mdl-6179936
ABSTRACT
The minor nucleoside 7-methylguanosine occurs in Escherichia coli 16 S ribosomal RNA at a single site. High pressure liquid chromatographic analysis shows that a single residue of 7-methylguanosine is also present in chloroplast 16 S ribosomal RNA, presumably at an analogous position in the sequence. Antibodies to 7-methylguanosine were induced in rabbits and shown to be highly specific for the intact methylated base. These antibodies were reacted with 30 S ribosomal subunits from E. coli and from the chloroplasts of Alaskan peas. These two types of ribosome have been shown to be topographically similar (Trempe, M. R., and Glitz, D. G. (1981) J. Biol. Chem. 256, 11873-11879). Electron microscopy of the subunit-antibody complexes showed similar subunit-IgG monomers and antibody-linked subunit dimers. In greater than 95% of the complexes observed for each type of ribosome, antibody contact was consistent with a single binding site, which places 7-methylguanosine near the junction of the upper one-third and lower two-thirds of the subunit and maximally distant from the platform. The analogous localization in both E. coli and chloroplast 30 S ribosomal subunits lends support to their proposed common evolutionary origin.
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Base de dados:
MEDLINE
Métodos Terapêuticos e Terapias MTCI:
Terapias_biologicas
Assunto principal:
RNA Bacteriano
/
RNA Ribossômico
/
Cloroplastos
/
Escherichia coli
/
Guanosina
Idioma:
En
Revista:
J Biol Chem
Ano de publicação:
1982
Tipo de documento:
Article