mix butter and graham cracker crumbs. pat into bottom and 2/3 way up the sides of a 10" spring form pan.
Beat cream cheese with an electric mixer until smooth. add sugar, beat well. add eggs one at a time,beating well after each egg.add vanilla and lemon juice. mix well. pour into pan. bake at 350 degrees for 50 to 60 minutes or until top is lightly browned and edges are split.
in the meantime mix sour cream, lemon juice,sugar and vanilla for the topping. add to cooked cheesecake, bake 5 minutes longer. serve chilled alone or with fruit topping.