DNA2

Description

The DNA2 (DNA replication helicase/nuclease 2) is a protein-coding gene located on chromosome 10.

DNA2 may refer to:

DNA2 is a key enzyme involved in both DNA replication and repair processes within the nucleus and mitochondria. During replication, it plays a crucial role in the processing of Okazaki fragments by cleaving long flaps that evade FEN1. These flaps, exceeding 27 nucleotides, are coated by RPA (replication protein A complex), leading to the recruitment of DNA2. DNA2 then cleaves the flap until it is sufficiently short to detach from RPA and become a suitable substrate for FEN1. Furthermore, DNA2 participates in the 5'-end resection of DNA during double-strand break (DSB) repair, where it is recruited by BLM (Bloom syndrome helicase) and mediates the cleavage of 5'-ssDNA, while preventing the cleavage of 3'-ssDNA due to the presence of RPA. Notably, DNA2 also contributes to the DNA replication checkpoint independently of its role in Okazaki fragment processing. DNA2 possesses diverse enzymatic activities, including ssDNA-dependent ATPase, 5'-3' helicase, and endonuclease activities. While the ATPase and endonuclease functions are well-established and essential for Okazaki fragment processing and DSB repair, the 5'-3' helicase activity remains a subject of debate. According to various studies, the helicase activity appears weak, and its specific role remains largely unclear. It has been suggested that the helicase activity might facilitate the movement of DNA2 along the flap, aiding its nuclease function.

DNA2 is also known as DNA2L, RTS4, hDNA2.

Associated Diseases

• Progressive external ophthalmoplegia with mitochondrial DNA deletions,autosomal dominant, 6
• DNA2-related mitochondrial DNA deletion syndrome
• Seckel syndrome 8
• Seckel syndrome