<p>This entry represents a DNA-binding helix-turn-helix domain found in the pogo family of transposable elements, the centromere protein Cenp-B, and yeast PCD2. There is extensive sequence similarity between Cenp-B and transposase proteins encoded by the pogo superfamily of transposable elements, which includes the human Tigger and Jerky elements [<cite idref="PUB00053387"/>]. The HTH domain is composed of three alpha-helices, with the second and third helices connected via a turn comprise the helix-turn-helix motif. Helix 3 is termed the recognition helix as it binds the DNA major groove, as in other HTHs [<cite idref="PUB00025705"/>]. This conserved DNA-binding domain is found in the following proteins:</p><p> <ul> <li>Cenp-B (major centromere autoantigen B or centromere protein B), which appears to organise arrays of centromere satellite DNA into a higher order structure that then direct centromere formation and kinetochore assembly in mammalian chromosomes. The N terminus of Cenp-B contains two DNA-binding HTH domains, which bind to adjacent major grooves of DNA: a psq-type HTH domain followed by a CenpB-type HTH domain, which together bind specifically to the Cenp-B box, which occurs in alpha-satellite DNA in human centromeres [<cite idref="PUB00035346"/>]. </li> </ul> </p><p> <ul> <li>Pogo family transposable elements includes both Tigger and Jerky elements [<cite idref="PUB00053387"/>]. Pogo contains two open reading frames flanked by inverted repeats. The N-terminal region of pogo transposase contains a Cenp-B-type HTH DNA-binding domain [<cite idref="PUB00053388"/>]. Mammalian jerky protein, involved in epileptic seizures in mice [<cite idref="PUB00053389"/>].</li> </ul> </p><p> <ul> <li>PDC2 (Pyruvate DeCarboxylase 2), which is a transcription factor required for the synthesis of the glycolytic enzyme pyruvate decarboxylase, required for high level expression of both the THI and the PDC genes. PDC2 may be important for a high basal level of PDC gene expression or play a positive role in the autoregulation control of PDC1 and PDC5 [<cite idref="PUB00053390"/>, <cite idref="PUB00053391"/>].</li> </ul> </p> Pogo transposase / Cenp-B / PDC2, DNA-binding HTH domain