Correlation of the exon/intron organization to the conserved domains of the mouse transcriptional corepressor TIF1 beta

TIF1 beta, a member of the transcriptional intermediary factor 1 family, ha s been reported to function as a corepressor for the large class of KRAB do main-containing zinc finger proteins of the Kruppel type. In this study, we report the genomic organization and nucleotide sequence of the mouse TIF1 beta gene. This gene comprises 17 coding exons located within 7 kb of genom ic DNA. Exon sizes vary from 37 bp (exon 10) to 901 bp (exon 1), and intron sizes range from 71 bp to 1843 bp. All introns have the conserved GT and A G dinucleotides present at the donor and acceptor sites, respectively. The functional/homology regions of the TIF1 beta protein are encoded by distinc t exons. The amino-terminal RING finger is encoded by two exons interrupted by a small intron. The B boxes lie within individual exons. Similarly to t he RING finger, the PHD finger is encoded by two exons. Three exons constit ute the carboxy-terminal bromodomain, and their position correlates well wi th the secondary structure elements of the domain as predicted by computer modeling. Taken together, these results will facilitate the genetic manipul ation of TIF1 beta for future in vivo structure-function studies. (C) 2000 Published by Elsevier Science B.V. All rights reserved.