E.L. James’ erotic best-seller Fifty Shades of Grey is soon to be a movie, starring Dakota Johnson as literature student Anastasia Steele and Charlie Hunnam as billionaire Christian Grey.  The book began as “Twilight” fan fiction and with its two sequels has become an international sensation.  Dakota Johnson, best known for the short-lived television series “Ben and Kate” and for vivid and confident work in small roles in “The Five Year Engagement” and “21 and Over,” is the daughter of Don Johnson and Melanie Griffith.  She is currently filming Shakespeare’s “Cymbeline” with Ethan Hawke and Milla Jovovich.  Charlie Hunnam was most recently seen in “Pacific Rim” operating a giant robot.  His roles have been exceptionally wide-ranging, from Victorian England as the title character in Nicholas Nickleby and as outlaw motorcyclist Jax Teller in Sons of Anarchy.