Transpolycis-decaprenyl diphosphate synthase (EC 2.5.1.86 Rv2361c (2Z6Z10Z14Z18Z22Z26Z30Z34E)-decaprenyl diphosphate synthase) is an enzyme with system name (2Z6E)-farnesyl-diphosphate:isopentenyl-diphosphate farnesylcistransferase (adding 7 isopentenyl units) .