The DEAD-box protein DDX43 (HAGE) is a dual RNA-DNA helicase and has a K-homology domain required for full nucleic acid unwinding activity.

The K-homology (KH) domain is a nucleic acid-binding domain present in many proteins but has not been reported in helicases. DDX43, also known as (elicase ntigen ne), is a member of the DEAD-box protein family. It contains a helicase core domain in its C terminus and a potential KH domain in its N terminus.

Mutational analysis of FANCJ helicase.

FANCJ is a superfamily 2 DNA helicase, which also belongs to the iron-sulfur domain containing helicases that include XPD, ChlR1 (DDX11), and RTEL1. Mutations in FANCJ are genetically linked to Fanconi anemia (FA), breast cancer, and ovarian cancer. FANCJ plays a critical role in genome stability and participates in DNA interstrand crosslink and double-strand break repair.