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The GTP binding protein Obg homolog ObgE is involved in ribosome maturation
Author(s) -
Sato Aya,
Kobayashi Gengo,
Hayashi Hiroshi,
Yoshida Hideji,
Wada Akira,
Maeda Maki,
Hiraga Sota,
Takeyasu Kunio,
Wada Chieko
Publication year - 2005
Publication title -
genes to cells
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.912
H-Index - 115
eISSN - 1365-2443
pISSN - 1356-9597
DOI - 10.1111/j.1365-2443.2005.00851.x
Subject(s) - 50s , biology , ribosomal protein , 23s ribosomal rna , ribosomal rna , ribosome , 5.8s ribosomal rna , ribosome biogenesis , eukaryotic ribosome , 30s , eukaryotic small ribosomal subunit , eukaryotic large ribosomal subunit , 5s ribosomal rna , eif4a , rna , microbiology and biotechnology , biochemistry , gene
Obg proteins belong to a subfamily of GTP binding proteins, which are highly conserved from bacteria to human. Mutations of obgE genes cause pleiotropic defects in various species but the function remained unclear. Here we examine the function of ObgE, the Obg homolog in Escherichia coli . The growth rate correlates with the amount of ObgE in cells. Co‐fractionation experiments further suggest that ObgE binds to 30S and 50S ribosomal subunits, but not to 70S ribosome. Pull‐down assays suggest that ObgE associates with several specific ribosomal proteins of 30S and 50S subunits, as well as RNA helicase CsdA. Purified ObgE cosediments with 16S and 23S ribosomal RNAs in vitro in the presence of GTP. Finally, mutation of ObgE affects pre‐16Sr‐RNA processing, ribosomal protein levels, and ribosomal protein modification, thereby significantly reducing 70S ribosome levels. This evidence implicates that ObgE functions in ribosomal biogenesis, presumably through the binding to rRNAs and/or rRNA‐ribosomal protein complexes, perhaps as an rRNA/ribosomal protein folding chaperone or scaffold protein.