Werner's syndrome is a rare autosomal recessive disorder characterized by accelerated aging that is caused by defects in the Werner syndrome ATP-dependent helicase gene (WRN). The protein encoded by this gene interacts with the exonuclease-containing N-terminal portion of the Werner protein. This protein has a ubiquitin-binding zinc-finger domain in the N-terminus, an ATPase domain, and two leucine zipper motifs in the C-terminus. It has sequence similarity to replication factor C family proteins and is conserved from E. coli to human. This protein likely accumulates at sites of DNA damage by interacting with polyubiquinated proteins and also binds to DNA polymerase delta and increases the initiation frequency of DNA polymerase delta-mediated DNA synthesis. This protein also interacts with nucleoporins at nuclear pore complexes. Two transcript variants encoding different isoforms have been isolated for this gene.