Turning USB wifi dongle On/Off by 3.3v

Hello all.I am a newbie and have just basic electronics knowledge.I have an old compaq laptop EVO N800v with a crappy wifi module inside the lid of LCD.By pressing F2 i can turn on and off the wifi module.My project is to replace the existing with a nicer wifi dongle inside a lid.I traced the pin outs on the interface and they are :
pin 1:Ground
Pin 2:Vcc +5v
Pin 3:F2 key controls it.3.3V=on off=0V
Pin 4:F2 key controls it.3.3V=on off=0V
Pin 5:Data +
Pin 6:Data -
Pin 7:Unknown
Pin 8:Ground
If i connect newer wifi dongle to +5v,gnd,Data+ and data-,It works fine however i cannot turn it on or off by pressing F2 key.I am looking to use a NPN transistor so that 3.3 volts can turn the +5 volts or gnd of the dongle.Could anybody please guide me how i can accomplish this by using few components and less battery drainage.Thanks in advance.