| Modification Notes |
DBR1 (debranching enzyme homolog 1) is a 544 amino acid protein that localizes to the nucleus and belongs to the lariat debranching enzyme family. Functioning at an optimal pH of 7.0, DBR1 uses divalent metal cations to catalyze the cleavage of the 2'-5' phosphodiester linkage at the branch point of lariat intron pre-mRNAs, thereby converting the lariat structures to linear molecules that are subject to degradation. Via its catalytic activity, DBR1 facilitates ribonucleotide turnover and is thought to participate in retroviral (specifically HIV-1) replication. Human DBR1 shares 79% homology with its mouse counterpart, suggesting a conserved role between species. DBR1 is expressed as two alternatively spliced isoforms that are encoded by a gene which maps to human chromosome 3. |