Well, I wondering about the fold by Seat 4. So if seat 5 is raising with a lot then isnt it most likely that he would have a pp here or just junk altogther? Then u have seat 1 calling (which puts seat 4 all in anyways basically) then if u can put him on QQ or worse than isnt this the right call? I dont think it would be that hard to put both players on low PP or just junk from Seat 5. Thus he is getting 3:1 on his money and he has a slightly better than 3:1 odds. Also, even if 5 has a hand like Ax, then he has a ~36% chance to win the hand. I think this all depends on the read on Seat 1. If one can put seat 1 on less worse than KK then he should make this call.
And yeah, why would Seat 1 leave himself with such little money for after the flop? This could make Seat 4 think that Seat 1 wants the call and have AA or KK, but him having these hands are not likely since he has AK already and this play seems weakish.