DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. a ribonucleoside 5'-triphosphate + RNA(n) = diphosphate + RNA(n+1) Binds 1 Mg(2+) ion per subunit. Binds 1 Zn(2+) ion per subunit. Belongs to the RNA polymerase beta' chain family. RpoC1 subfamily. Young tissue from this organism is photosynthetic and contains some thylakoids, although the photosynthetic activity does not exceed the light compensation point.