ParB-like nuclease Proteins containing this domain, appear to be related to the <taxon tax_id="562">Escherichia coli</taxon> plasmid protein ParB, which preferentially cleaves single-stranded DNA. ParB also nickssupercoiled plasmid DNA preferably at sites with potential single-strandedcharacter, like AT-rich regions and sequences that can form cruciform structures. ParB also exhibits 5--3 exonuclease activity.