They are indeed a Turkish company, and as EverettWA already mentioned, they have a passenger subsidiary (called MNG Pax).
MNG Cargo airlines operates 6 A300F-planes (TC-MNA/B/C/D/G/J).
MNG Pax operates 1 A300 (TC-MNE - now operating in blue TUI-clrs, does lots of flights between BRU
and AYT) and 5 B734's (TC-MNF/H/I/L/M) (I flew this summer with TC
-MNI & TC
-MNM). The B734's fly from all around Europe (Belgium, Germany, Switzerland, etc.) to (touristic) destinations in turkey.
That's quite all I (think I) know. Please correct me if I'm wrong.