Abstract
As a result of the nucleotide sequence analysis of an aphid endosymbiont's operon homologous to the Escherichia coli groE, we noted that directional base substitutions tending toward an increase of A + T content represent an obvious evolutionary trend in this prokaryotic operon, housed for a long period by an eukaryotic cell. This result, when taken together with previous reports, raised the possibility that genomic DNA of prokaryotes residing in an eukaryotic cell is subject to A/T-biased directional mutation pressure and/or both negative and positive selection operating under conditions specific to the intracellular environments.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Adenine / metabolism*
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Animals
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Aphids / microbiology
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Bacterial Proteins / genetics*
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Bacterial Proteins / metabolism
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Base Sequence
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Biological Evolution
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Chaperonins*
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Cloning, Molecular
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Codon
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DNA, Bacterial
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Escherichia coli / genetics
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Escherichia coli Proteins
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Gram-Negative Bacteria / genetics*
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Gram-Negative Bacteria / metabolism
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Heat-Shock Proteins / genetics*
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Heat-Shock Proteins / metabolism
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Molecular Sequence Data
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Operon*
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Sequence Homology, Nucleic Acid
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Symbiosis
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Thymine / metabolism*
Substances
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Bacterial Proteins
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Codon
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DNA, Bacterial
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Escherichia coli Proteins
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GroE protein, E coli
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Heat-Shock Proteins
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SymL protein, Bacteria
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Chaperonins
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Adenine
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Thymine