Phage-type rna polymerases in higher plants

摘要

Plastids harbor a multi-subunit RNA polymerase (RNAP) highly similar to eubacterial RNA polymerase, encoded by the plastid rpoA, rpoB and rpoC genes. The rpo genes have been found in all plant species so far investigated, with the exception of the parasite Epifagus virginiana. The eubacterial-like plastid RNA polymerase has been designated PEP (= plastid encoded polymerase). Several lines of evidence implicate the existence of a second RNA polymerase in the plastids of higher plants which is encoded in the nucleus (NEP = nuclear encoded polymerase. The plastid enzyme, NEP, functions in a coordinated manner, which can be described as "division of labour", together with the plastid encoded PEP.