Preheat oven to 325°F (165°C). Prepare crust by mixing crumbs and melted butter, pressing into a 9-inch springform pan.
Beat cream cheese, sour cream, and sugar until smooth. Add eggs one at a time, then stir in lemon juice, zest, and vanilla. Pour over crust.
Bake at 325°F (165°C) for 1 hour, or until center is almost set. Cool to room temperature, then refrigerate for 3-4 hours.
Beat egg whites until soft peaks form. Gradually add sugar and cream of tartar, beating until stiff peaks form. Spread lemon curd over cheesecake, then top with meringue.
Bake at 375°F (190°C) for 10 minutes, or until meringue is golden. Chill in refrigerator for at least 1 hour before serving.
Notes
Do not cover the meringue while chilling, as it may cause the meringue to collapse.