This is a conserved region from DNA primase. This corresponds to the Toprim domain common to DnaG primases, topoisomerases, OLD family nucleases and RecR proteins. Both DnaG motifs IV and V are present in the alignment, the DxD (V) motif may be involved in Mg2+ binding and mutations to the conserved glutamate (IV) completely abolish DnaG type primase activity. DNA primase EC:220.127.116.11 is a nucleotidyltransferase it synthesizes the oligoribonucleotide primers required for DNA replication on the lagging strand of the replication fork; it can also prime the leading stand and has been implicated in cell division. This family also includes the atypical archaeal A subunit from type II DNA topoisomerases. Type II DNA topoisomerases catalyze the relaxation of DNA supercoiling by causing transient double strand breaks.