In short, yes you can. Music is art, and there are no rules. Just guidelines you may choose to follow. As krushing said, drums and bass may sound a bit odd if not centered, but again, it's up to you. Some Beatles records have this kind of panning (guitars to one side, drums and bass to the others), some Black Sabbath albums (Paranoid for example) has it's bass all the way to the left and guitars all the way to the right.