In chloroplasts, transcription of plastid genes is mediated By two types of RNA polymerase: plastid-encoded RNA polymerase (PEP) and nuclear encoded RNA polymerase (NEP) . PEP is composed of four core suBunits (a, B,B,B) and a promoter recognition suBunit (sigmafactor) . RpoC1 (ATCG00180) is the B suBunit of PEP.
