We report the cloning and detailed characterization of a new transcript containing two SNF2_N domains and one PHD domain. The SNF2_N domain is often seen in proteins involved in such processes as transcription regulation (for example, SNF2, MOT1), DNA repair (for example, ERCC6, RAD16), DNA recombination (for example, RAD 54), and chromatin unwinding (for example, ISWI). The PHD domain is a C4HC3 zinc-finger-like motif found in nuclear proteins thought to be involved in chromatin-mediated transcriptional regulation. Shotgun sequence analysis of a mouse BAC clone identified several exons with homologies to a variety of repair protein genes in the database. Inter-exon polymerase chain reaction followed by 5′ rapid amplification of cloned ends and identification of expressed sequence tags for the 3′ end led to the cloning of a 7,225-base-pair cDNA with an open reading frame consisting of 4,848 base pairs. The human homologue was cloned by polymerase chain reaction between the expressed sequence tags identified by a BLAST search of the mouse sequence, followed by 5′ rapid amplification of cloned ends. The coding sequence of the two genes is 83% identical at the amino acid level. Northern blot analysis shows a transcript of approximately 7.5 kilobases in all tissues examined with both human and mouse complementary DNAs as a probe. We have mapped the human cDNA to 6q23, a region reported to contain a tumor suppressor locus by several laboratories, including our own. We are currently generating antibodies, and we will present preliminary functional studies.