Plant AT-rich sequence- and zinc-binding protein 1 (PLATZ1), is the first member to be isolated of a class of zinc dependent DNA binding proteins. PLATZ1 was isolated from pea cDNA and has significant homology to several predicted proteins from the genomes of other plants, that yet remain uncharacterized. Multiple alignments among these paralogous proteins show that several cysteine and histidine residues are invariant in two distant regions on the protein, C-x(2)-H-x(11)-C-x(2)-C-x((4-5))-C-x(2)-C-x((3-7))-H-x(2)-H and C-x(2)-C-x((10-11))-C-x(3)-C. Both regions have been described to be necessary for zinc-dependent DNA binding. PLATZ1 has been shown to nonspecifically bind AT-rich sequences, and is thought to repress transcription of AT-rich sequences (PMID:11600698).