Negatively regulates its own expression and that of the subsequent genes in the proximal part of the division and cell wall (dcw) gene cluster. Acts by binding directly to DNA. May also regulate the expression of genes outside the dcw cluster. Dodecamer. Negatively autoregulated. Mutants have no detectable phenotype under standard laboratory conditions. They are more resistant to trimethoprim than wild-type cells. Overproduction is lethal and perturbs cell division. It destabilizes the divisome, but does not affect FtsZ levels or prevent Z ring assembly. Co-overproduction of RsmH (MraW) protects the cell from the toxic effects of MraZ overproduction (PubMed:24659771). Belongs to the MraZ family.