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A geminivirus replication protein is a sequence-specific DNA binding protein.

E P Fontes·V A Luckow·L Hanley-Bowdoin
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Abstract

The genome of the geminivirus tomato golden mosaic virus (TGMV) consists of two circular DNA molecules designated as components A and B. The A component encodes the only viral protein, AL1, that is required for viral replication. We showed that AL1 interacts specifically with TGMV A and B DNA by using an immunoprecipitation assay for AL1:DNA complex formation. In this assay, a monoclonal antibody against AL1 precipitated AL1:TGMV DNA complexes, whereas an unrelated antibody failed to precipitate the complexes. Competition assays with homologous and heterologous DNAs established the specificity of AL1:DNA binding. AL1 produced by transgenic tobacco plants and by baculovirus-infected insect cells exhibited similar DNA binding activity. The AL1 binding site maps to 52 bp on the left side of the common region, a 235-bp region that is highly conserved between the two TGMV genome components. The AL1:DNA binding site does not include the putative hairpin structure that is conserved in the common regions or the equivalent 5' intergenic regions of all geminiviruses. These studies demonstrate that a geminivirus replication protein is a sequence-specific DNA binding protein, and the studies have important implications for the role of this protein in virus replication.

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Base SequenceBinding SitesBinding, CompetitiveDNA, ViralDNA-Binding ProteinsElectrophoresis, Polyacrylamide GelMolecular Sequence DataMosaic VirusesPlants, Genetically ModifiedViral ProteinsVirus ReplicationJournal ArticleResearch Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, Non-P.H.S.

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E P Fontes, V A Luckow, L Hanley-Bowdoin. 1992. A geminivirus replication protein is a sequence-specific DNA binding protein.. https://doi.org/10.1105/tpc.4.5.597

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