Induces host cell lysis. Inhibits host MurA activity thereby blocking the synthesis of murein precursors necessary for the host cell wall biosynthesis. May be responsible for the attachment to the host pilus. Interacts with host MurA; this interaction inhibits the first step in host cell wall synthesis. Interacts with the capsid protein dimers. A single copy of the maturation protein is present in the virion. Belongs to the Levivirus maturation protein family.