DNA helicase, DEXX box type <p>This entry represents DEXX type DNA helicases, such as the hexameric essential helicases PcrA from Gram-positive bacteria and Rep and UvrD from Gram-negative bacteria [<cite idref="PUB00035958"/>]. PcrA is essential for cell growth in Bacillus species, as it is required for rolling circle replication, unwinding DNA using an active inchworm mechanism [<cite idref="PUB00035955"/>]. UvrD from <taxon tax_id="562">Escherichia coli</taxon> is a superfamily 1 (SF1) helicase involved in several DNA metabolic processes, including recombination and repair [<cite idref="PUB00035956"/>], while Rep affects the rate of replication fork progression in E. coli and is required for the replication of certain phages [<cite idref="PUB00035957"/>].</p>