Abstract
7SL RNA is an RNA component of a signal recognition particle (SRP) and the 7SL RNA genes were transcribed by RNA polymerase III (Pol III). Class III genes are classified with 4 types by their promoter organization. Type 1 (5S rRNA gene) and type 2 (tRNA gene) possess promoter sequences within transcribed region (inner promoter). Type 3 genes include only upstream elements. Type 4 genes have both inner promoters and upstream elements. Hitherto, plant 7SL genes were believed that they belonged to type 3 gene because evident conservative sequence did not find in the 7SL RNA transcribed region. However, we have proved that the plant 7SL RNA genes have inner promoter by using tobacco in vitro transcription system and mutated DNA templates. Here we concluded that the plant 7SL RNA genes are belonging to type 4.
