Torsin 1B (TOR1B)

By exon trapping on chromosome 9q34, screening fetal brain, adult frontal cortex, and adult liver cDNA libraries, and 5-prime and 3-prime RACE, Ozelius et al. (1997) cloned TOR1B, which they designated DQ1. The deduced 289-amino acid protein has a calculated molecular mass of more than 32 kD. TOR1B shares 69% amino acid identity with TOR1A, and both proteins contain an ATP-binding domain, 2 protein kinase C phosphorylation sites, a casein kinase II phosphorylation site, several N-myristoylation sites, and 6 conserved cysteines. Northern blot analysis detected expression of a 2.8-kb TOR1B transcript in adult brain, but not in fetal brain.TOR1B lies centromeric to TOR1A, and the 2 genes face in opposite orientations with their 3-prime ends about 2 kb apart.