This is a conserved region from DNA primase. This corresponds to the Toprim domain common to DnaG primases, topoisomerases, OLDfamily nucleases and RecR proteins [1]. Both DnaG motifs IV andV are present in the alignment, the DxD (V) motif may beinvolved in Mg2+ binding and mutations to the conservedglutamate (IV) completely abolish DnaG type primase activity[1]. DNA primase EC:2.7.7.6 is a nucleotidyltransferase itsynthesises the oligoribonucleotide primers required for DNAreplication on the lagging strand of the replication fork; itcan also prime the leading stand and has been implicated in celldivision [2]. This family also includes the atypical archaeal Asubunit from type II DNA topoisomerases [4]. Type II DNAtopoisomerases catalyse the relaxation of DNA supercoiling bycausing transient double strand breaks.