A door and door frame assembly having a door closing mechanism adapted to provide sufficient closing force to the door so that the door engages and sufficiently compresses a gasket between the door and the door frame to prevent electromagnetic interference, such as environmental radio frequencies, from passing between the door and door frame. The door closing mechanism moves a strike plate relative to the door frame to close the door once it is latched to the strike plate. The strike plate is moveable between an extended position and a retracted position relative to the door frame. In the extended position, the gasket is not sufficiently compressed between the door and door frame even though the door is latched. In the retracted position, the gasket is sufficiently compressed between the door and the door frame to attenuate the passage of electromagnetic interference between the door and door frame.