SAP protein revealed small sequence motifs that are characteristic for transcriptional regulators. A long serine-rich stretch (STSSSSS) is present at the amino terminus of the protein. This amino-terminal serine-rich region is adjacent to a glycine-rich region (DNGAGGSGG). Together these two stretches compose serine/glycine-rich domain, which is a motif often found in eukaryotic transcriptional regulators. SAP encodes a novel plant specific protein containing a few hallmarks of a transcriptional regulator.
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