The next two genes of the cluster (plcE and plcT) encode proteins of 227 AA and 214 AA, respectively. Both have conserved ATP-binding domains linked to proteins of the ABC transporter family and based on homology to their equivalents from GaaA and AciB clusters, they are most likely involved in the secretion of PlcA. The downstream plcB and plcC genes are located in positions that are different from their homologs in the clusters for GaaA and AciB production (Figure 2). The function of the proteins coded by these two genes is still unknown, but their presence in all of the clusters from circular bacteriocins clearly indicates that they must play an important role (8).