title: The POU domain is a bipartite DNA-binding structure.
abstract: The POU domain (pronounced 'pow') is a highly charged 155-162-amino-acid (aa) region of sequence similarity contained within three mammalian transcription factors. Pt-1 (ref. 2), Oct-1 (ref. 3) and Oct-2 (ref. 4), and the product of the nematode gene unc-86 (ref. 5) which is involved in determining neural cell lineage. This domain consists of two subdomains, a C-terminal homoeo domain and an N-terminal POU-specific region separated by a short nonconserved linker; the sequence relationship shows that the POU homoeo domains form a distinct POU-related family. In the ubiquitous and lymphoid-specific octamer-motif binding proteins Oct-1 and Oct-2, the POU domain is sufficient for sequence-specific DNA binding. Homoeobox domains contain a helix-turn-helix DNA-binding motif, first identified in bacterial repressors. The helix-turn-helix region of the POU domain is important for DNA binding and, in other classes of homoeo-containing proteins, the entire homoeo domain is sufficient for DNA binding; thus the new POU-specific region could be involved in other functions such as protein-protein interactions. Nevertheless, we show here that in fact the POU domain is a novel bipartite DNA-binding structure in which the POU homoeo and POU-specific regions form two subdomains that are both required for DNA binding but are held together by a flexible linker.
authors.affiliation: Cold Spring Harbor Laboratory, New York 11724.
authors.forename: R A
authors.initials: RA
authors.lastname: Sturm
authors.forename: W
authors.initials: W
authors.lastname: Herr
mesh_terms: D001483:Base Sequence; D004247:DNA / Q000378:metabolism*; D005801:Genes, Homeobox; D005814:Genes, Viral; D008969:Molecular Sequence Data; D009154:Mutation; D013539:Simian virus 40 / Q000235:genetics; D018139:Simplexvirus / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
chemical_list: D014157:Transcription Factors; D004247:DNA