Plant nuclear factor ASF-1 binds to an essential region of the nopaline synthase promoter.
We have characterized a tobacco nuclear factor that binds to the -118 region of the nopaline synthase (nos) promoter from the Ti plasmid of Agrobacterium tumefaciens. The binding site for this factor, identified by DNase I footprinting, encompasses the region from -138 to -103 of the nos promoter. This region, which contains a potential Z-DNA-forming sequence, was previously shown to be essential for nos promoter activity in transgenic tobacco. A synthetic 21-base pair sequence from the protected region (from -131 to -111), designated as nos-1, was sufficient for factor recognition in vitro. In transgenic tobacco, a tetramer of nos-1 can confer leaf and root expression when fused upstream of a truncated 35 S promoter from the cauliflower mosaic virus. Mutations at the two TGACG-like motifs in nos-1 abolish factor binding while preserving the potential for Z-DNA formation. A tetramer of the nos-1 mutant sequence has no significant activity above background when tested in transgenic tobacco. Competition experiments with activation sequence factor (ASF)-1 binding sites from the 35 S promoter of cauliflower mosaic virus (as-1) and the wheat histone H3 promoter (hex-1) demonstrate that ASF-1 is the factor that binds to nos-1.
Lam
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E
Laboratory of Plant Molecular Biology, Rockefeller University, New York, New York 10021.
Katagiri
F
F
Chua
N H
NH
D000594:Amino Acid Oxidoreductases / Q000235:genetics*; D001483:Base Sequence; D001665:Binding Sites; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005822:Genetic Vectors; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes; D010944:Plants / Q000378:metabolism*; D010947:Plants, Toxic; D010957:Plasmids; D011401:Promoter Regions, Genetic; D012231:Rhizobium / Q000201:enzymology / Q000235:genetics*; D014026:Nicotiana / Q000378:metabolism*
D004268:DNA-Binding Proteins; D015345:Oligonucleotide Probes; D000594:Amino Acid Oxidoreductases; C021883:nopaline synthase