scholarly journals Spectroscopic evidence for the uneven distribution of adenine and uracil residues in ribosomal ribonucleic acid of Drosophila melanogaster and of Plasmodium knowlesi and its possible evolutionary significance

1976 ◽  
Vol 155 (3) ◽  
pp. 465-475 ◽  
Author(s):  
R A Cox ◽  
E Godwin ◽  
J R Hastings
Keyword(s):  
Drosophila Melanogaster ◽  
Plasmodium Knowlesi ◽  
Nucleotide Composition ◽  
Evolutionary Significance ◽  
Base Pairs ◽  
Parasite Plasmodium ◽  
Ribosomal Ribonucleic Acid ◽  
Principal Species ◽  
Polynucleotide Chain ◽  
Hypochromic Effect

RNA was isolated from subribosomal particles of the malaria parasite Plasmodium knowlesi. The nucleotide composition (mole fraction) of the principal species was obtained (S-rRNA, 0.295A, 0.36U, 0.25G, 0.105C: L-rRNA, 0.326A, 0.31U, 0.228G, 0.144C). Ribosomal RNA was also isolated from Drosophila melanogaster. Optical properties of these A + U-rich species were measured. In all four cases analysis of the hypochromic effect revealed that adenine and uracil residues tended to form clusters along the polynucleotide chain. A substantial fraction of residues was located in bihelical regions of approx. 50% G-C base pairs or in regions of approx. 30-35% G-C base pairs. The possible evolutionary significance of these results was considered on the basis of comparison with properties of rRNA from bacteria (Escherichia coli) and a mammal (rabbit reticulocyte).

scholarly journals Studies on the 3′-terminal sequences of the large ribosomal ribonucleic acid of different eukaryotes and those associated with ‘hidden’ breaks in heat-dissociable insect 26S ribonucleic acid

1974 ◽  
Vol 141 (3) ◽  
pp. 617-625 ◽  
Author(s):  
John Shine ◽  
John A. Hunt ◽  
Lynn Dalgarno
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Drosophila Melanogaster ◽  
Ribonucleic Acid ◽  
Galleria Mellonella ◽  
Terminal Sequence ◽  
6S Rna ◽  
Ribosomal Ribonucleic Acid ◽  
Higher Eukaryotes ◽  
26S Rrna ◽  
Polynucleotide Chain

The 3′-terminal sequences associated with the large rRNA complex from a range of eukaryotes were determined after pancreatic or T1-ribonuclease digestion of RNA terminally labelled with [3H]isoniazid. In all higher eukaryotes examined except Drosophila melanogaster, the 3′-terminal sequences Y-G-UOH and G-C-UOH were demonstrated for the large RNA component(s) and for 6S RNA respectively. The 3′-terminal sequence of Saccharomyces cerevisiae 26S RNA was Y-G-UOH and that of 6S RNA Y-A-U-U-UOH. Three 3′-terminal sequences were found in equimolar amounts in the heat-dissociable 26S rRNA characteristic of insect ribosomes. These were Y-G-U-G-UOH, Y-C-G-UOH and G-C-UOH for cultured Antheraea eucalypti cells, Y-G-UOH, Y-G-UOH and G-C-UOH for Galleria mellonella larvae and Y-C-G-AOH, Y-G-U-AOH and G-Y-U-GOH for Drosophila melanogaster flies. Thus the introduction of the central scission in insect 26S rRNA results in the generation of a unique 3′-terminus and does not arise from random cleavage of the polynucleotide chain.

scholarly journals Adaptation, Ecology, and Evolution of the Halophilic Stromatolite ArchaeonHalococcus hamelinensisInferred through Genome Analyses

Archaea ◽  
2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Reema K. Gudhka ◽  
Brett A. Neilan ◽  
Brendan P. Burns
Keyword(s):  
Unknown Function ◽  
Energy Production ◽  
Extreme Environment ◽  
Evolutionary Significance ◽  
Base Pairs ◽  
Protein Coding ◽  
Inorganic Ion ◽  
Damage Repair ◽  
Genome Analyses

Halococcus hamelinensiswas the first archaeon isolated from stromatolites. These geomicrobial ecosystems are thought to be some of the earliest known on Earth, yet, despite their evolutionary significance, the role of Archaea in these systems is still not well understood. Detailed here is the genome sequencing and analysis of an archaeon isolated from stromatolites. The genome ofH. hamelinensisconsisted of 3,133,046 base pairs with an average G+C content of 60.08% and contained 3,150 predicted coding sequences or ORFs, 2,196 (68.67%) of which were protein-coding genes with functional assignments and 954 (29.83%) of which were of unknown function. Codon usage of theH. hamelinensisgenome was consistent with a highly acidic proteome, a major adaptive mechanism towards high salinity. Amino acid transport and metabolism, inorganic ion transport and metabolism, energy production and conversion, ribosomal structure, and unknown function COG genes were overrepresented. The genome ofH. hamelinensisalso revealed characteristics reflecting its survival in its extreme environment, including putative genes/pathways involved in osmoprotection, oxidative stress response, and UV damage repair. Finally, genome analyses indicated the presence of putative transposases as well as positive matches of genes ofH. hamelinensisagainst various genomes of Bacteria, Archaea, and viruses, suggesting the potential for horizontal gene transfer.

scholarly journals Identical 3′-terminal octanucleotide sequence in 18S ribosomal ribonucleic acid from different eukaryotes. A proposed role for this sequence in the recognition of terminator codons

1974 ◽  
Vol 141 (3) ◽  
pp. 609-615 ◽  
Author(s):  
John Shine ◽  
Lynn Dalgarno
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Synthesis ◽  
Drosophila Melanogaster ◽  
Ribosomal Rna ◽  
Ribonucleic Acid ◽  
18S Rrna ◽  
Base Sequence ◽  
Terminal Sequence ◽  
Ribosomal Ribonucleic Acid ◽  
Rrna Species

The 3′-terminal sequence of 18S ribosomal RNA from Drosophila melanogaster and Saccharomyces cerevisiae was determined by stepwise degradation from the 3′-terminus and labelling with [3H]isoniazid. The sequence G-A-U-C-A-U-U-AOH was found at the 3′-terminus of both 18S rRNA species. Less extensive data for 18S RNA from a number of other eukaryotes are consistent with the same 3′-terminal sequence, and an identical sequence has previously been reported for the 3′-end of rabbit reticulocyte 18S rRNA (Hunt, 1970). These results suggest that the base sequence in this region is strongly conserved and may be identical in all eukaryotes. As the 3′-terminal hexanucleotide is complementary to eukaryotic terminator codons we discuss the possibility that the 3′-end of 18S rRNA may have a direct base-pairing role in the termination of protein synthesis.

Nuclear and mitochondrial DNA of the primate malarial parasite Plasmodium knowlesi

1985 ◽  
Vol 14 (2) ◽  
pp. 199-209 ◽  
Author(s):  
Donald H. Williamson ◽  
Robert J.M. Wilson ◽  
Paul A. Bates ◽  
Shirley McCready ◽  
Francine Perler ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Plasmodium Knowlesi ◽  
Malarial Parasite ◽  
Parasite Plasmodium

scholarly journals Novel vectors of the zoonotic malaria parasite, Plasmodium knowlesi, in two districts of Sarawak, Malaysian Borneo

2018 ◽  
Vol 73 ◽  
pp. 75
Author(s):  
J. Ang Xin De ◽  
K. Abdul Kadir ◽  
D.S. Awang Mohamad ◽  
A. Matusop ◽  
K. Yaman ◽  
...  
Keyword(s):  
Malaria Parasite ◽  
Plasmodium Knowlesi ◽  
Zoonotic Malaria ◽  
Parasite Plasmodium ◽  
Malaysian Borneo

scholarly journals Pseudouridine modification in the tRNA(Tyr) anticodon is dependent on the presence, but independent of the size and sequence, of the intron in eucaryotic tRNA(Tyr) genes.

1988 ◽  
Vol 8 (8) ◽  
pp. 3332-3337 ◽  
Author(s):  
Y Choffat ◽  
B Suter ◽  
R Behra ◽  
E Kubli
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Drosophila Melanogaster ◽  
Trna Gene ◽  
Xenopus Laevis Oocytes ◽  
Wild Type ◽  
Base Pairs ◽  
Consensus Sequences ◽  
Trna Precursor ◽  
Tyr Gene ◽  
Six Genes

In Saccharomyces cerevisiae, pseudouridine formation in the middle position of the tRNA(Tyr) anticodon (psi 35) is dependent on the presence of the intron in the tRNA(Tyr) gene (Johnson and Abelson, Nature 302:681-687, 1983). Drosophila melanogaster tRNA(Tyr) genes contain introns of three size classes: 20 or 21 base pairs (bp) (six genes), 48 bp (one gene), and 113 bp (one gene). As in yeast, removal of the intron led to loss of psi 35 in the anticodon when transcription was assayed in Xenopus laevis oocytes. All Drosophila intron sizes supported psi 35 formation. The same results were obtained with the homologous X. laevis tRNA(Tyr) genes containing introns of 12 or 13 bp or with a deleted intron. The introns of yeast (Nishikura and DeRobertis, J. Mol. Biol. 145:405-420, 1981), D. melanogaster, and X. laevis tRNA(Tyr) wild-type genes, while they all supported psi 35 synthesis, did not share any consensus sequences. As discussed, these results, taken together, suggest that for appropriate function the psi 35 enzyme in the X. laevis oocyte needs the presence of an unqualified intron in the tRNA gene and a tRNA(Tyr)-like structure in the unprocessed tRNA precursor.

scholarly journals An intracellular simian malarial parasite (Plasmodium knowlesi) induces stage-dependent alterations in membrane phospholipid organization of its host erythrocyte

1987 ◽  
Vol 246 (1) ◽  
pp. 103-108 ◽  
Author(s):  
P Joshi ◽  
G P Dutta ◽  
C M Gupta
Keyword(s):  
Developmental Stages ◽  
Plasmodium Knowlesi ◽  
Membrane Phospholipid ◽  
Malarial Parasite ◽  
Merocyanine 540 ◽  
Parasite Plasmodium ◽  
Normal Monkey ◽  
Infected Cells ◽  
Membrane Isolation ◽  
Different Sources

The membrane phospholipid organization in monkey erythrocytes harbouring different developmental stages of the simian malarial parasite Plasmodium knowlesi was studied using phospholipase A2 from two different sources and Merocyanine 540 as the external-membrane probes. Experiments were done to confirm that the phospholipases did not penetrate into the infected cells or hydrolyse phospholipids during membrane isolation. The parasite-free erythrocyte membrane was isolated by differential centrifugation or by using the cationic beads Affi-Gel 731. The purity of the membranes was established by optical and electron microscopy, and by assaying the parasite-specific enzyme glutamate dehydrogenase. About 10% of the phosphatidylethanolamine and none of phosphatidylserine were hydrolysed by the phospholipases in intact normal monkey erythrocytes. However, accessibility of these aminophospholipids to the enzymes was significantly enhanced in the infected cells under identical conditions. The degree of this enhancement depended on the developmental stage of the intracellular parasite, but not on the parasitaemia levels in the infected monkeys, and increased with the parasite growth inside the cells. Analogously, Merocyanine 540 was found to label the trophozoite- or schizont-infected erythrocytes, but not the ring-infected or normal cells. These results demonstrate that the intracellular malarial parasite produces stage-dependent alterations in the membrane phospholipid organization of its host erythrocyte.

scholarly journals Sequences involved in temperature and ecdysterone-induced transcription are located in separate regions of a Drosophila melanogaster heat shock gene.

1986 ◽  
Vol 6 (2) ◽  
pp. 663-673 ◽  
Author(s):  
E Hoffman ◽  
V Corces
Keyword(s):  
Drosophila Melanogaster ◽  
Heat Shock ◽  
Dna Sequences ◽  
Germ Line ◽  
Initiation Site ◽  
P Element ◽  
Heat Shock Gene ◽  
Base Pairs ◽  
Consensus Sequences ◽  
Shock Gene

The transcriptional regulation of the Drosophila melanogaster hsp27 (also called hsp28) gene was studied by introducing altered genes into the germ line by P element-mediated transformation. DNA sequences upstream of the gene were defined with respect to their effect on steroid hormone-induced and heat-induced transcription. These two types of control were found to be separable; the sequences responsible for 80% of heat-induced expression were located more than 1.1 kilobases upstream of the RNA initiation site, while the sequences responsible for the majority of ecdysterone induction were positioned downstream of the site at -227 base pairs. We have determined the DNA sequence of the intergenic region separating hsp23 and hsp27 and have located putative heat shock and ecdysterone consensus sequences. Our results indicate that the heat shock promoter of the hsp27 gene is organized quite differently from that of hsp70.

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