Abstract
A new extrachromosomal DNA, EcOYW1, was cloned from the onion yellows phytoplasma (OY-W). Southern blot and PCR analysis showed that EcOYW1 is not present in the OY-M, a mild symptom line derived from OY-W. We determined the complete nucleotide sequence of EcOYW1; it is a circular dsDNA of 7.0 kbp in length, which contains seven ORFs. ORF1 encoded a homologue of the geminivirus Rep protein. Western immunoblot analysis revealed that this Rep homologue is expressed in OY-W infected plants, suggesting that EcOYW1 replicates via a geminivirus-like rolling-circle replication mechanism. EcOYW1 is the first phytoplasmal extrachromosomal DNA shown to express encoded genes.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Amino Acid Sequence
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Chromosomes, Bacterial / genetics*
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Chrysanthemum cinerariifolium / microbiology*
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Cloning, Molecular
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DNA Helicases / genetics
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DNA Helicases / metabolism*
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DNA Replication
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DNA, Bacterial / genetics
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DNA-Binding Proteins*
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Geminiviridae / genetics*
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Geminiviridae / metabolism
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Molecular Sequence Data
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Plant Diseases / microbiology
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Sequence Analysis, DNA
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Sequence Homology, Amino Acid
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Tenericutes / genetics*
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Tenericutes / metabolism
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Tenericutes / pathogenicity
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Trans-Activators / genetics
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Trans-Activators / metabolism*
Substances
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DNA, Bacterial
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DNA-Binding Proteins
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Trans-Activators
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replication initiator protein
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DNA Helicases