Lariat debranching enzyme is a protein that in humans is encoded by the DBR1 gene.

The RNA lariat debranching enzyme, or DBR1, specifically hydrolyzes 2-prime-to-5-prime branched phosphodiester bonds at the branch point of excised lariat intron RNA and converts them into linear molecules.[supplied by OMIM, Jul 2002].
Function: Cleaves the 2'-5' phosphodiester linkage at the branch point of lariat intron pre-mRNAs after splicing and converts them into linear molecules that are subsequently degraded. It thereby facilitates ribonucleotide turnover. It may also participate in retrovirus replication via a RNA lariat intermediate in cDNA synthesis.