Build knowledge bot using deep learning
It is definitely possible, but obviously to a certain extent. What you need, is a sequence to sequence model trained on questions and answers data of a domain. Denny Britz has this amazing blog post on impelementing a  retreival based chatbot trained on ubuntu dialog corpus using tensorflow. Go through the post to understand the difference between retreival based and generative model chatbot. The efficiency and efficacy of such a bot, is another question all together and rigorous research is going on to improve such bots. IBM watson does it pretty well as mentioned in the comments.