Primosomal protein N', also known as ATP-dependent helicase PriA, is a component of the primosome, involved in replication, repair and recombination. PriA is a multifunctional enzyme that mediates the essential process of restarting prematurely terminated DNA replication reactions in bacteria PMID:17483094,PMID:23264623. PriA presents a two-domain architecture, with an N-terminal DNA-binding domain (DBD) and a C-terminal helicase domain (HD). Structural studies reveal a central helicase core surrounded by an array of DNA-binding elements. These elements include two domains within the DBD, a 3(prime) DNA-binding domain (3primeBD) and an unusual circularly permuted winged helix (WH) domain, and two domains within the HD, a Cys-rich region (CRR) that binds two Zn2+ ions and a C-terminal domain (CTD) which shows unexpected similarity to the S10 subunit of the bacterial ribosome PMID:24379377. Structural domains comprising this superfamily share the structure of the 3(prime) DNA binding domain.