The GTP binding protein Obg homolog ObgE is involved in ribosome maturation

Sato, Aya; Kobayashi, Gengo; Hayashi, Hiroshi; Yoshida, Hideji; Wada, Akira; Maeda, Maki; Hiraga, Sota; Takeyasu, Kunio; Wada, Chieko

doi:10.1111/j.1365-2443.2005.00851.x

Cited by 123 publications

(177 citation statements)

References 60 publications

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“…Both E. coli and C. crescentus have been reported to copurify with the ribosome, although this interaction has been reported to be weak (for Caulobacter) (Lin et al, 2004) or variable (for E. coli ) (Kobayashi et al, 2001;Sato et al, 2005). It has been suggested that ObgE is required for ribosome biogenesis and that observed cell cycle effects may be an indirect consequence of loss of translation capacity (Sato et al, 2005).…”

Section: Obge Depletion Does Not Reduce Translational Capacitymentioning

confidence: 99%

“…Previous studies of Obg orthologues have examined different temperature-sensitive alleles and point mutations to deplete functional Obg in Gram-negative bacteria (Kobayashi et al, 2001;Datta et al, 2004;Sato et al, 2005;Sikora et al, 2006). The results of these studies have suggested various and diverse cellular roles, including ribosome biogenesis, stress response and chromosome segregation.…”

Section: Obge Is Necessary For Efficient Chromosome Partitioningmentioning

confidence: 99%

“…Obg from Streptomyces ceolicolor controls mycelium formation in response to intracellular pools of guanine nucleotides (Okamoto and Ochi, 1998). A mutational analysis of the C. crescentus orthologue suggests accumulation of 50S ribosomal subunits at the expense of 70S assembled ribosomes (Lin et al, 2004), a phenotype also seen in E. coli (Sato et al, 2005). However, the essential function of Caulobacter Obg (CgtA) appears to be progression through the cell cycle (Datta et al, 2004) rather than defects in ribosome assembly.…”

Section: Introductionmentioning

confidence: 99%

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Chromosome segregation control by Escherichia coli ObgE GTPase

Foti

Persky²,

Ferullo

et al. 2007

Molecular Microbiology

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SummaryEscherichia coli cells depleted of the conserved GTPase, ObgE, show early chromosome-partitioning defects and accumulate replicated chromosomes in which the terminus regions are colocalized. Cells lacking ObgE continue to initiate replication, with a normal ratio of the origin to terminus. Localization of the SeqA DNA binding protein, normally seen as punctate foci, however, was disturbed. Depletion of ObgE also results in cell filamentation, with polyploid DNA content. Depletion of ObgE did not cause lethality, and cells recovered fully after expression of ObgE was restored. We propose a model in which ObgE is required to license chromosome segregation and subsequent cell cycle events.

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Section: Obge Depletion Does Not Reduce Translational Capacitymentioning

confidence: 99%

Section: Obge Is Necessary For Efficient Chromosome Partitioningmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Chromosome segregation control by Escherichia coli ObgE GTPase

Foti

Persky²,

Ferullo

et al. 2007

Molecular Microbiology

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“…Both proteins have a binding site on ribosomes, and they could interact with L23, a ribosomal protein on the peptide exit tunnel of ribosomes (Gu et al, 2003). Era, ObgE, SelB, and YchF could also interact with ribosomes (Sayed et al, 1999;Leipe et al, 2002;Sato et al, 2005). The binding of these GTPases to ribosomes reduced the amount of dissociated proteins, which could improve denatured citrate synthase refolding, thereby decreasing the reactivation level.…”

Section: Discussionmentioning

confidence: 99%

Study on the chaperone properties of conserved GTPases

et al. 2012

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As a large family of hydrolases, GTPases are widespread in cells and play the very important biological function of hydrolyzing GTP into GDP and inorganic phosphate through binding with it. GTPases are involved in cell cycle regulation, protein synthesis, and protein transportation. Chaperones can facilitate the folding or refolding of nascent peptides and denatured proteins to their native states. However, chaperones do not occur in the native structures in which they can perform their normal biological functions. In the current study, the chaperone activity of the conserved GTPases of Escherichia coli is tested by the chemical denaturation and chaperone-assisted renaturation of citrate synthase and α-glucosidase. The effects of ribosomes and nucleotides on the chaperone activity are also examined. Our data indicate that these conserved GTPases have chaperone properties, and may be ancestral protein folding factors that have appeared before dedicated chaperones.

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“…The other motifs indicate GTP binding, GTPase, methyltransferase, peptidyl-prolyl isomerase, helicase activities, and chaperone function. These proteins may have roles in ribosome maturation or assembly, RNA folding, rRNA processing, protein assembly, and subunit structure stabilization similar to what has been observed in other organisms (41)(42)(43)(44)(45)(46)(47)(48)(49). Intriguingly helicase activity was recently identified in ribosomes that could account for its ability to translate through downstream mRNA secondary structure (50).…”

Section: Sequence Characteristics Of Mt Ribosomal Proteins-mostmentioning

confidence: 99%

Trypanosoma brucei Mitochondrial Ribosomes

Zı́ková

Panigrahi

Dalley

et al. 2008

Molecular & Cellular Proteomics

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Although eukaryotic mitochondrial (mt) ribosomes evolved from a putative prokaryotic ancestor their compositions vary considerably among organisms. We determined the protein composition of tandem affinity-purified Trypanosoma brucei mt ribosomes by mass spectrometry and identified 133 proteins of which 77 were associated with the large subunit and 56 were associated with the small subunit. Comparisons with bacterial and mammalian mt ribosomal proteins identified T. brucei mt homologs of L2-4, L7/12, L9, L11, L13-17, L20 -24, L27-30, L33, L38, L43, L46, L47, L49, L52, S5, S6, S8, S9, S11, S15-18, S29, and S34, although the degree of conservation varied widely. Sequence characteristics of some of the component proteins indicated apparent functions in rRNA modification and processing, protein assembly, and mitochondrial metabolism implying possible additional roles for these proteins. Nevertheless most of the identified proteins have no homology outside Kinetoplastida implying very low conservation and/or a divergent function in kinetoplastid mitochondria. Molecular & Cellular Proteomics 7:1286 -1296, 2008. Mt1 ribosomes appear to be structurally variable to a considerable extent from one organism to another and have undergone some major remodeling during their evolution including loss of RNA and acquisition of proteins (1, 2). Their sedimentation coefficient (S) values vary between 50 S in Leishmania, 70 -74 S in fungi, 55 S in metazoans, and 78 S in higher plants (3-6). Tandem mass spectrometry has been successfully applied to the analysis of the protein composition of ribosomes from several organelles including bovine mitochondria (5, 7-10), fungal mitochondria (11, 12), and chloroplasts (13,14). Mammalian ribosomes have about the same mass as bacterial ribosomes but half as much RNA and over twice as much proteins. Proteomics analysis of bovine mt ribosomes (9, 10) identified 78 different proteins, which include homologs of Escherichia coli ribosomal proteins and 36 additional proteins that presumably were acquired during eukaryotic evolution. Many of these new ribosomal proteins are distinct, having no closely related homologs in bacterial or eukaryotic cytoplasmic ribosomes. The estimated number of proteins within mammalian mt ribosomes has ranged from about 85 to more than 100, for yeast mitochondria it is 78 proteins, and for chloroplast mitochondria it is 49 proteins. The feature of protein richness implies that the reduced rRNA sizes are compensated by some protein components that might have been recruited to mt ribosomes during the course of evolution (15).Trypanosoma and Leishmania are protozoan parasites belonging to the order Kinetoplastida that are the causative agents of several devastating tropical diseases such as African sleeping sickness, Chagas disease, and leishmaniasis. Protein synthesis in the mitochondria of these unicellular flagellates has unusual features. The transcripts from most genes encoded in the trypanosomatid mt DNA are posttranscriptionally modified via extensive and precise ins...

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The GTP binding protein Obg homolog ObgE is involved in ribosome maturation

Cited by 123 publications

References 60 publications

Chromosome segregation control by Escherichia coli ObgE GTPase

Chromosome segregation control by Escherichia coli ObgE GTPase

Study on the chaperone properties of conserved GTPases

Trypanosoma brucei Mitochondrial Ribosomes

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