Fedora 25 : Gnome Software Center and Curl not working behind proxy

**Update - I'm on Fedora 25 now but the issue is still unsolved.** I have Fedora 25 Workstation on my laptop. The internet access is through proxy server only. I have successfully configured proxy settings for dnf and wget. I can install and updates packages using dnf from terminal. wget and firefox also work. But Gnome Software Center and curl do not work. Everytime I try to install something from software center, I get the error > Curl error (7): Couldn't connect to server for > https://mirrors.fedoraproject.org/metalink?repo=fedora-24&arch=x86_64 > [Failed to connect to mirrors.fedoraproject.org port 443: Connection > refused] What I have tried so far: 1 : Set proxy settings using dconf-editor **(Source) ** 2 : Manually add proxy info to /etc/PackageKit/PackageKit.conf **(Source1) ** **(Source2) ** 3 : Add proxy info to ~/.bash_profile, ~/.curlrc, /etc/profile **(Source) ** None of these have worked. How do I get Gnome Software Center working?