The gatekeeper with the military drives cannot open a jump for any size of ship since the military drive capacity (15,000) is less than the ship size (45,000).
The gate keeper can jump itself using the commercial jump drive since it has commercial engines.
AS previously noted by multiple responders, the commercial drive cannot be used to jump the limeleaf since the limeleaf has military engines, and the military drive cannot be used to jump the limeleaf since the military drive capacity is less than the gatekeeper size, it does not matter that it is larger than the limeleaf's 7500 since it is non-functional being on a ship that is larger than the capacity.