All the replies above are good and offer sound advice. However, I am going to approach it a bit differently.
To get the job, don't focus on what you do or don't know. Focus on your ability and desire to learn. Leverage your previous accomplishments to show that what you learn, you apply.
You may not like this job, but you will learn something valuable from it, I guarantee you that. Take the job and learn what you can and keep looking! You know what you like to do and generally what you are looking for. Look while learning. Remember, your taking a job, not getting married... :-)
I have been in industry for 31 years and due to the volatility of the industries I was in ended up with a number of jobs, and sitting on both sides of the interview table. When I look for a candidate, I look for someone who can learn, not someone who already knows it all. I don't care how much they know, they don't know it in MY environment, which means they have pre-conceived notions of what problems are to be solved and how to solve them. It can be much harder for an experienced individual to step into a new environment than it is for someone fresh.(incidentally, I have been that experienced person and when I got the job, it was miserable simply because I had pre-conceived notions, and a lack of flexibility. Bad move on my part, and on the part of the hiring manager)
All that being said, don't take a job you know you will hate, ever! You can not learn effectively in such an environment. If you see it as an opportunity to expand your skill set and understanding of your industry from an alternate perspective, then it is worth the investment of time. If you can't see it that way, don't go there, it won't be a happy thing and can sour you.
Best of luck to you!