Even Deepak had music from DBSK's one other song as well (it was either Mirotic or Hey! Don't bring Me Down, can't be too sure now) in one of Rashmi's acts - it was in the beginning few weeks after Rashmi-Deepaks entry in JDJ5. I was quite surprised no one mentioned it back then. And even now, no one mentioned Purple Line either.
That's the real-dance that DBSK do or rather used to do. The dance in JDJ5 is nothing compared to their dancing. It's a joke apart from a very few performances.
For those wondering which bit, here is the original Japanese song (for Korean version, search on Youtube. I can't seem to find it):
For those who want to watch it on YT: https://www.youtube.com/watch?v=Z6kBFUqPYSM
For those who want English translated lyrics: http://ongaku-seikatsu.blogspot.co.uk/2008/01/dbsk-lyrics-translations.html
I tried embedding the video here but it doesn't seem to be working.