Correlation of the exon/intron organization to the conserved domains of the mouse transcriptional corepressor TIF1β

TIF1 beta, a member of the transcriptional intermediary factor 1 family, has been reported to function as a corepressor for the large class of KRAB domain-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 genomic 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 AG dinucleotides present at the donor and acceptor sites, respectively. The functional/homology regions of the TIF1 beta protein are encoded by distinct 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 the RING finger, the PHD finger is encoded by two exons. Three exons constitute the carboxy-terminal bromodomain, and their position correlates well with the secondary structure elements of the domain as predicted by computer modeling. Taken together, these results will facilitate the genetic manipulation of TIF1 beta for future in vivo structure-function studies. (C) 2000 Published by Elsevier Science B.V. All rights reserved.