Vivek,
The Shure SM58 provides a positive signal on pin 2 with respect to pin 3 when pressure is put on the diaphragm (when sound hits it). Pin 1 is connected to ground. To connect this microphone to an unbalanced mixer, you just connect pins 3 and 1 to ground and use pin 2 as your signal output. This is all you have when you purchase a cable with XLR on one end and 1/4" phono jack on the other end.
You will not see any difference in the output unless you are running massive lengths of microphone cables.
MP