Members of this family are phage (or prophage-region) homologs of the bacterial homohexameric replicative helicase DnaB. Some phage may rely on host DnaB, while others encode their own verions. This model describes the largest phage-specific clade among the close homologs of DnaB, but there are, or course, other DnaB homologs from phage that fall outside the scope of this model. [Mobile and extrachromosomal element functions, Prophage functions]