Urk. I, on the other hand, would have guessed httpd.conf because I've got piles of those* but no apache2.conf. But you need someone who speaks apache. (I don't. Most of the time I can fake it with a solid RegEx background. This is not most of the time.)
:: looking vaguely around for g1 or someone like him ::
fwiw, Apache [httpd.apache.org] says it's normally called httpd.conf ;) I know that you already know that; I'm putting in the link so the next passing reader knows I'm not making it up out of my head.
What's in your apache2.conf file? All of mine just have miscellaneous bits of stuff-- obviously not complete config files. Are they meant as include files? If so, I have no idea what they'd be included in.
* I do not fully understand why there are 158 items on my hard drive with the .conf extension. That would seem to be 157 more than I need. Four of them are called apache-something. But the "real" config file used by MAMP is called httpd.conf