scholarly journals Simplification of Ribosomes in Bacteria with Tiny Genomes

2020 ◽  
Vol 38 (1) ◽  
pp. 58-66 ◽  
Author(s):  
Daria D Nikolaeva ◽  
Mikhail S Gelfand ◽  
Sofya K Garushyants
Keyword(s):  
Ribosomal Protein ◽  
Ribosomal Rna ◽  
Ribosomal Proteins ◽  
Protein Biosynthesis ◽  
Large Subunit ◽  
Protein Composition ◽  
Small Subunit ◽  
Bacterial Genomes ◽  
Shine Dalgarno Sequence

Abstract The ribosome is an essential cellular machine performing protein biosynthesis. Its structure and composition are highly conserved in all species. However, some bacteria have been reported to have an incomplete set of ribosomal proteins. We have analyzed ribosomal protein composition in 214 small bacterial genomes (<1 Mb) and found that although the ribosome composition is fairly stable, some ribosomal proteins may be absent, especially in bacteria with dramatically reduced genomes. The protein composition of the large subunit is less conserved than that of the small subunit. We have identified the set of frequently lost ribosomal proteins and demonstrated that they tend to be positioned on the ribosome surface and have fewer contacts to other ribosome components. Moreover, some proteins are lost in an evolutionary correlated manner. The reduction of ribosomal RNA is also common, with deletions mostly occurring in free loops. Finally, the loss of the anti-Shine–Dalgarno sequence is associated with the loss of a higher number of ribosomal proteins.

scholarly journals Simplification of ribosomes in bacteria with tiny genomes

2019 ◽  
Author(s):  
Daria D. Nikolaeva ◽  
Mikhail S. Gelfand ◽  
Sofya K. Garushyants
Keyword(s):  
Ribosomal Protein ◽  
Ribosomal Proteins ◽  
Protein Biosynthesis ◽  
Large Subunit ◽  
Protein Composition ◽  
Small Subunit ◽  
Genome Reduction ◽  
Bacterial Genomes ◽  
Shine Dalgarno Sequence

AbstractThe ribosome is an essential cellular machine performing protein biosynthesis. Its structure and composition are highly conserved in all species. However, some bacteria have been reported to have an incomplete set of ribosomal proteins. We have analyzed ribosomal protein composition in 214 small bacterial genomes (< 1 Mb) and found that although the ribosome composition is fairly stable, some ribosomal proteins may be absent, especially in bacteria with dramatically reduced genomes. The protein composition of the large subunit is less conserved than that of the small subunit. We have identified the set of frequently lost ribosomal proteins and demonstrated that they tend to be situated on the ribosome surface and have fewer contacts to other ribosome components. Moreover, some proteins are lost in an evolutionary correlated manner. The reduction of rRNA is also common in bacteria with tiny genomes with deletions mostly occurring in free loops. Finally, the loss of the anti-Shine-Dalgarno sequence is associated with the genome reduction, the number of lost ribosomal proteins, and with the loss of bL9 and TF.

Rapid evolution in sequence and length of the nuclear-located gene for mitochondrial L2 ribosomal protein in cereals

Genome ◽  
2006 ◽  
Vol 49 (3) ◽  
pp. 275-281 ◽  
Author(s):  
Selvi Subramanian ◽  
Linda Bonen
Keyword(s):  
Amino Acids ◽  
Ribosomal Protein ◽  
Ribosomal Rna ◽  
Ribosomal Proteins ◽  
Rna Binding ◽  
Large Subunit ◽  
Rapid Evolution ◽  
Comparative Sequence Analysis ◽  
Marchantia Polymorpha ◽  
Peptidyl Transferase

The L2 ribosomal protein is typically one of the most conserved proteins in the ribosome and is universally present in bacterial, archaeal, and eukaryotic cytosolic and organellar ribosomes. It is usually 260–270 amino acids long and its binding to the large-subunit ribosomal RNA near the peptidyl transferase center is mediated by a β-barrel RNA-binding domain with 10 β strands. In the diverse land plants Marchantia polymorpha (liverwort) and Oryza sativa (rice), the mitochondrial-encoded L2 ribosomal protein is about 500 amino acids long owing to a centrally located expansion containing the β3–β4 strand region. We have determined that, in wheat, the functional rpl2 gene has been trans ferred to the nucleus and much of the plant-specific internal insert has been deleted. Its mRNA is only 1.2 kb, and two expressed copies in wheat encode proteins of 318 and 319 amino acids, so they are considerably shorter than the maize nuclear-located rpl2 gene of 448 codons. Comparative sequence analysis of cereal mitochondrial L2 ribosomal proteins indicates that the mid region has undergone unexpectedly rapid evolution during the last 60 million years.Key words: mitochondria, ribosomal protein, plants, evolutionary gene transfer.

scholarly journals Ribosome Biogenesis in African Trypanosomes Requires Conserved and Trypanosome-Specific Factors

2014 ◽  
Vol 13 (6) ◽  
pp. 727-737 ◽  
Author(s):  
Khan Umaer ◽  
Martin Ciganda ◽  
Noreen Williams
Keyword(s):  
Ribosomal Protein ◽  
Ribosomal Proteins ◽  
Ribosome Biogenesis ◽  
Large Subunit ◽  
Ribosomal Subunit ◽  
Small Subunit ◽  
5S Rrna ◽  
Content Type ◽  
African Trypanosomes ◽  
Ribosomal Protein L5

ABSTRACTLarge ribosomal subunit protein L5 is responsible for the stability and trafficking of 5S rRNA to the site of eukaryotic ribosomal assembly. InTrypanosoma brucei, in addition to L5, trypanosome-specific proteins P34 and P37 also participate in this process. These two essential proteins form a novel preribosomal particle through interactions with both the ribosomal protein L5 and 5S rRNA. We have generated a procyclic L5 RNA interference cell line and found that L5 itself is a protein essential for trypanosome growth, despite the presence of other 5S rRNA binding proteins. Loss of L5 decreases the levels of all large-subunit rRNAs, 25/28S, 5.8S, and 5S rRNAs, but does not alter small-subunit 18S rRNA. Depletion of L5 specifically reduced the levels of the other large ribosomal proteins, L3 and L11, whereas the steady-state levels of the mRNA for these proteins were increased. L5-knockdown cells showed an increase in the 40S ribosomal subunit and a loss of the 60S ribosomal subunits, 80S monosomes, and polysomes. In addition, L5 was involved in the processing and maturation of precursor rRNAs. Analysis of polysomal fractions revealed that unprocessed rRNA intermediates accumulate in the ribosome when L5 is depleted. Although we previously found that the loss of P34 and P37 does not result in a change in the levels of L5, the loss of L5 resulted in an increase of P34 and P37 proteins, suggesting the presence of a compensatory feedback loop. This study demonstrates that ribosomal protein L5 has conserved functions, in addition to nonconserved trypanosome-specific features, which could be targeted for drug intervention.

Depletion and Reconstitution of Active E. Coli Ribosomes

1975 ◽  
Vol 33 ◽  
pp. 640-641
Author(s):  
M. Boublik ◽  
W. Hellmann ◽  
F. Jenkins
Keyword(s):  
Protein Biosynthesis ◽  
Large Subunit ◽  
High Resolution Electron Microscopy ◽  
Small Subunit ◽  
Structure And Function ◽  
Biologically Active ◽  
Biological Macromolecules ◽  
E Coli ◽  
Resolution Electron ◽  
And Function

Correlations between structure and function of biological macromolecules have been studied intensively for many years, mostly by indirect methods. High resolution electron microscopy is a unique tool which can provide such information directly by comparing the conformation of biopolymers in their biologically active and inactive state. We have correlated the structure and function of ribosomes, ribonucleoprotein particles which are the site of protein biosynthesis. 70S E. coli ribosomes, used in this experiment, are composed of two subunits - large (50S) and small (30S). The large subunit consists of 34 proteins and two different ribonucleic acid molecules. The small subunit contains 21 proteins and one RNA molecule. All proteins (with the exception of L7 and L12) are present in one copy per ribosome.This study deals with the changes in the fine structure of E. coli ribosomes depleted of proteins L7 and L12. These proteins are unique in many aspects.

scholarly journals The proteins of Xenopus ovary ribosomes

1971 ◽  
Vol 125 (4) ◽  
pp. 1091-1107 ◽  
Author(s):  
P J Ford
Keyword(s):  
Potassium Chloride ◽  
Ribosomal Proteins ◽  
Large Subunit ◽  
Buoyant Density ◽  
Small Subunit ◽  
Chemical Methods ◽  
Ribosomal Subunits ◽  
Molecular Weights ◽  
Caesium Chloride ◽  
Chloride Treatment

1. The preparation of ribosomes and ribosomal subunits from Xenopus ovary is described. 2. The yield of once-washed ribosomes (buoyant density in caesium chloride 1.601g·cm-3; 44% RNA, 56% protein by chemical methods) was 10.1mg/g wet wt. of tissue. 3. Buoyant density in caesium chloride and RNA/protein ratios by chemical methods have been determined for ribosome subunits produced by 1.0mm-EDTA or 0.5m-potassium chloride treatment and also for EDTA subunits extracted with 0.5m-, 1.0m- or 1.5m-potassium chloride, 4. Analysis of ribosomal protein on acrylamide gels at pH4.5 in 6m-urea reveals 24 and 26 bands from small and large EDTA subunits respectively. The actual numbers of proteins are greater than this, as many bands are obviously doublets. 5. Analysis of the proteins in the potassium chloride extract and particle fractions showed that some bands are completely and some partially extracted. Taking partial extraction as an indication of possible doublet bands it was found that there were 12 and 20 such bands in the small and large subunits respectively, making totals of 36 and 46 proteins. 6. From the measured protein contents and assuming weight-average molecular weights for the proteins of large and small subunits close to those observed for eukaryote ribosomal proteins it is possible to compute the total numbers of protein molecules per particle. It appears that too few protein bands have been identified on acrylamide gels to account for all the protein in the large subunit, but probably enough for the small subunit.

Comparison of the Effect of Various Methods of Dissociation on the Protein Composition of Rat Liver Ribosomal Subunits

1975 ◽  
Vol 53 (9) ◽  
pp. 935-942 ◽  
Author(s):  
Nabil Hanna ◽  
Claude Godin
Keyword(s):  
Rat Liver ◽  
Ribosomal Proteins ◽  
Gradient Centrifugation ◽  
Polyacrylamide Gel Electrophoresis ◽  
Protein Composition ◽  
Small Subunit ◽  
Protein Patterns ◽  
Major Loss ◽  
Centrifugation Technique ◽  
High Concentrations

Rat liver ribosomes were dissociated into subunits using EDTA, sodium pyrophosphate, high concentrations of KCl, as well as by incubation with puromycin in presence of 0.5 M KCl. The subunits obtained were analyzed using the density gradient centrifugation technique and their ribosomal proteins were separated by means of two-dimensional polyacrylamide gel electrophoresis. The ribosomal protein patterns of the two subunits isolated using each of the dissociating method were compared to the protein patterns of monosomes prepared by puromycin treatment alone. Our results revealed that the use of chelating agents to dissociate the ribosomes resulted in the loss of some ribosomal proteins from the small subunit. On the other hand, the use of KCl in high concentrations to dissociate the ribsosomes did not appear to cause any major loss of proteins from the ribosomes except for some acidic proteins.

New observations on Miculenchus Andrássy, 1959 (Nematoda: Tylenchidae) with descriptions of two new and one known species from Iran

Nematology ◽  
2019 ◽  
Vol 21 (9) ◽  
pp. 937-956 ◽  
Author(s):  
Yousef Panahandeh ◽  
Ebrahim Pourjam ◽  
Sergio Álvarez-Ortega ◽  
Farahnaz Jahanshahi Afshar ◽  
Majid Pedram
Keyword(s):  
New Species ◽  
Ribosomal Rna ◽  
Large Subunit ◽  
Small Subunit ◽  
Lsu Rdna ◽  
Natural Forests ◽  
Electron Microscopic ◽  
Pharyngeal Bulb ◽  
Ribosomal Rna Gene ◽  
Molecular Approaches

Summary During nematological surveys in grasslands and natural forests of north and north-western Iran, three species of Miculenchus, including two new and one known species, were recovered and characterised based upon morphological and molecular approaches. Miculenchus brevisalvus n. sp., the first new species, is mainly characterised by its short females 334-388 μm long and with a short 6.0-7.5 μm long stylet, pyriform to pyriform-elongate pharyngeal bulb, 4-8 μm long post-uterine sac (PUS), offset rounded spermatheca filled with small spheroid sperm, elongate conoid tail 62-83 μm long with a sharp tip, and males with simple cloacal lips. Miculenchus muscus n. sp., the second new species, is characterised by a combination of the following features: body 401-467 μm long, well-developed protuberant labial plate at the anterior end under light microscopy, stylet 7-9 μm long, pyriform pharyngeal bulb, PUS 4-9 μm long, gradually narrowing conical tail 62-74 μm long with a finely pointed or sharp end and bearing several fine bristles at tip, and a male with projecting cloacal lips. Both newly described species were morphologically compared with four currently known species of the genus, viz., M. elegans, M. salmae, M. salvus, and M. tesselatus. Miculenchus salmae was also recovered and reported from Iran for the first time. It is mainly characterised by lacking a PUS and the characteristic vagina shape. Miculenchus muscus n. sp. and M. salmae were both characterised using scanning electron microscopic images, yielding new morphological observations for the genus. All three species are studied for their molecular phylogenetic characters using sequences of near-full length fragments of the small subunit ribosomal RNA gene (SSU rDNA) and the D2-D3 expansion segments of the large subunit ribosomal RNA gene (LSU rDNA D2-D3). In both SSU and LSU phylogenies, all currently sequenced species of Miculenchus formed a monophyletic group with maximal clade support in both Bayesian inference and maximum likelihood analysis.

scholarly journals Five Fungal Pathogens Are Responsible for Bayberry Twig Blight and Fungicides Were Screened for Disease Control

2020 ◽  
Vol 8 (5) ◽  
pp. 689 ◽  
Author(s):  
Wenjun Li ◽  
Ming Hu ◽  
Yang Xue ◽  
Zhijun Li ◽  
Yanfei Zhang ◽  
...  
Keyword(s):  
Ribosomal Rna ◽  
Fungal Pathogens ◽  
Large Subunit ◽  
Elongation Factor ◽  
Morphological Characteristics ◽  
Its Region ◽  
Small Subunit ◽  
Field Application ◽  
Financial Loss ◽  
Twig Blight

Bayberry (Myrica rubra) is a commercial fruit in China. For the past seven years, twig blight disease has been attacking bayberry plantations in Shantou City, Guangdong Province, China, leading to destructive damage and financial loss. In this study, five fungal species associated with twig dieback and stem blight were identified based on morphological characteristics combined with multilocus sequence analysis (MLSA) on the internal transcribed spacer (ITS) region, partial sequences of β-tubulin (tub2), translation elongation factor 1-α (tef1-α), large subunit ribosomal RNA (LSU) and small subunit ribosomal RNA (SSU) genes, which are Epicoccum sorghinum, Neofusicoccum parvum, Lasiodiplodia theobromae, Nigrospora oryzae and a Pestalotiopsis new species P. myricae. P. myricae is the chief pathogen in fields, based on its high isolation rate and fast disease progression after inoculation. To our knowledge, this is the first study reporting the above five fungi as the pathogens responsible for bayberry twig blight. Indoor screening of fungicides indicates that Prochloraz (copper salt) is the most promising fungicide for field application, followed by Pyraclostrobin, 15% Difenoconazole + 15% Propiconazole, Difenoconazole and Myclobutanil. Additionally, Bacillus velezensis strain 3–10 and zeamines from Dickeya zeae strain EC1 could be used as potential ecofriendly alternatives to control the disease.

Subcellular distribution of ribosomal proteins in Dictyostelium discoideum

1990 ◽  
Vol 68 (5) ◽  
pp. 839-845
Author(s):  
S. Ramagopal
Keyword(s):  
Ribosomal Proteins ◽  
Large Subunit ◽  
Small Subunit ◽  
Cellular Slime Mold ◽  
Developmentally Regulated ◽  
Two Dimensional Gel Electrophoresis ◽  
Coomassie Blue ◽  
Cellular Slime ◽  
State Growth

The distribution of ribosomal proteins in monosomes, polysomes, the postribosomal cytosol, and the nucleus was determined during steady-state growth in vegetative amoebae. A partitioning of previously reported cell-specific ribosomal proteins between monosomes and polysomes was observed. L18, one of the two unique proteins in amoeba ribosomes, was distributed equally among monosomes and polysomes. However S5, the other unique protein, was abundant in monosomes but barely visible in polysomes. Of the developmentally regulated proteins, D and S6 were detectable only in polysomes and S14 was more abundant in monosomes. The cystosol revealed no ribosomal proteins. On staining of the nuclear proteins with Coomassie blue, about 18, 7 from 40S subunit and 11 from 60S subunit, were identified as ribosomal proteins. By in vivo labeling of the proteins with [35S]methionine, 24 of the 34 small subunit proteins and 33 of the 42 large subunit proteins were localized in the nucleus. For the majority of the ribosomal proteins, the apparent relative stoichiometry was similar in nuclear preribosomal particles and in cytoplasmic ribosomes. However, in preribosomal particles the relative amount of four proteins (S11, S30, L7, and L10) was two- to four-fold higher and of eight proteins (S14, S15, S20, S34, L12, L27, L34, and L42) was two- to four-fold lower than that of cytoplasmic ribosomes.Key words: cellular slime mold, cell-specific ribosomal proteins, nucleus, cytoplasm, two-dimensional gel electrophoresis.

scholarly journals A novel small-subunit ribosomal protein of yeast mitochondria that interacts functionally with an mRNA-specific translational activator.

1990 ◽  
Vol 10 (9) ◽  
pp. 4590-4595 ◽  
Author(s):  
T W McMullin ◽  
P Haffter ◽  
T D Fox
Keyword(s):  
Ribosomal Protein ◽  
Ribosomal Proteins ◽  
Mitochondrial Gene ◽  
Ribosomal Subunit ◽  
Nuclear Gene ◽  
Small Subunit ◽  
Rrna Gene ◽  
Mitochondrial Translation ◽  
Activator Proteins ◽  
Translational Activator

Mitochondrial translation of the mRNA encoding cytochrome c oxidase subunit III (coxIII) specifically requires the action of three position activator proteins encoded in the nucleus of Saccharomyces cerevisiae. Some mutations affecting one of these activators, PET122, can be suppressed by mutations in an unlinked nuclear gene termed PET123. PET123 function was previously demonstrated to be required for translation of all mitochondrial gene products. We have now generated an antibody against the PET123 protein and have used it to demonstrate that PET123 is a mitochondrial ribosomal protein of the small subunit. PET123 appears to be present at levels comparable to those of other mitochondrial ribosomal proteins, and its accumulation is dependent on the presence of the 15S rRNA gene in mitochondria. Taken together with the previous genetic data, these results strongly support a model in which the mRNA-specific translational activator PET122 works by directly interacting with the small ribosomal subunit to promote translation initiation on the coxIII mRNA.

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