the 5S rRNA subunit (component of the 60S ribosomal subunit) is transcribed by RNA polymerase III.

Transcription of rRNA yields a long precursor molecule (45S pre-rRNA), which still contains the internal transcribed spacer (ITS) and external transcribed spacer (ETS). Further processing is needed to generate the 18S RNA, 5.8S, and 28S RNA molecules. In