Cyanobacterial evolution: results of 16S ribosomal ribonucleic acid sequence analyses

1979 ◽  
Vol 57 (6) ◽  
pp. 879-888 ◽  
Author(s):  
L. Bonen ◽  
W. F. Doolittle ◽  
G. E. Fox
Keyword(s):  
Ribonucleic Acid ◽  
Phylogenetic Diversity ◽  
Filamentous Cyanobacteria ◽  
Sequence Analyses ◽  
Group Iii ◽  
Computer Aided ◽  
Agmenellum Quadruplicatum ◽  
Ribosomal Ribonucleic Acid ◽  
Red Algal

We report here the sequences of oligonucleotides released by T1-ribonuclease digestion of the 16S ribosomal RNA's (rRNA's) of the unicellular cyanobacteria Agmenellum quadruplicatum (strain BG-1) and Synechococcus 7502. We compare them with sequences previously obtained for the 16S rRNA's of six other cyanobacteria and two chloroplasts, and conclude that: (i) Synechocystis-like unicells form a discrete cluster which also (and surprisingly) includes Agmenellum quadruplicatum, usually considered to be a Synechococcus; (ii) filamentous cyanobacteria of the genera Nostoc and Fischerella arose from within the Synechocystis group; (iii) phylogenetic diversity (and hence presumably evolutionary antiquity) within the Synechococcus group is very great; and (iv) red algal chloroplasts are of definite cyanobacterial origin, while Euglena chloroplasts are of separate and quite possibly noncyanobacterial origin. We also present the results of a computer-aided search among the 10 oligonucleotide 'catalogues' for families of related but nonidentical sequences. Examination of these families reinforces the above conclusions.

Ribosomal ribonucleic acid cistron homologies among Hyphomicrobium and various other bacteria

1977 ◽  
Vol 23 (4) ◽  
pp. 478-481 ◽  
Author(s):  
Richard L. Moore
Keyword(s):  
Cell Wall ◽  
Ribonucleic Acid ◽  
Deoxyribonucleic Acid ◽  
Gram Positive ◽  
Gram Negative ◽  
Group Iii ◽  
Hybrid Formation ◽  
Group I ◽  
Ribosomal Ribonucleic Acid ◽  
Taxonomic Implications

The extent of hybrid formation between the ribosomal ribonucleic acid (r-RNA) of Hyphomicrobium strain B-522 and deoxyribonucleic acid (DNA) from bacteria of 21 different genera was examined. Three generalized groupings were formed. Group I (72–100%) consisted entirely of other strains of Hyphomicrobium. Representatives of the genera Rhodopseudomonas, Chromatium, Caulobacter, Prosthecomicrobium, Rhodomicrobium, Hyphomonas, and Hyphomicrobium made up group II (49–69%). The remaining Gram-negative, Gram-positive, and cell wall – less bacteria fell into group III (12–40%). The taxonomic implications of these results are discussed.

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.

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