I see that there is some python3-pyqt5 packages for your distribution: (http://packages.ubuntu.com/search?keywords=python3-pyqt5). Maybe simpler to install it this way.
Also, maybe you want to use the "python" command, probably calls a wrong version of python (check if you have only one version or more and if this is the version needed by pyqt5).
For example, I had to compile/install two times: one for python-2.7, and an other for python-3.4. I use PyQT5 with python-3.4 and PyQT4 with python-2.7. For call the good command python, I would use in your case: python3.4 configure.
If this doesn't work, I think there are some compatibility problems.
In this case, just check all and go back to the first step installation (from all packages needed: python, QT, and dependencies).