A laparoscopic suturing instrument (10) comprises an end effector (200), a shaft assembly (100), and a drive assembly (530, 600). The end effector comprises needle receiving arms (210, 250) operable to grasp a needle (50). The drive assembly comprises drive members that are rotatable about respective drive axes (513a, 513b, 513c, 513d) that are perpendicular to the axis of the shaft assembly. The drive assembly is operable to drive the needle receiving arms to selectively engage and disengage the needle; and to selectively pass the needle from one needle receiving arm to the other needle receiving arm. The drive assembly provides an interface to a controller that is operable via a remote user interface. The drive assembly may include helical gears (728), clutch assemblies (86, 862, 864), a rack (850) and pinion (852), or other components to convert motion of the drive members into motion at the end effector.