transcription by RNA polymerase III rRNA transcription 5S class rRNA transcription by RNA polymerase III GO:0042791 biological_process 5S class rRNA transcription from RNA polymerase III type 1 promoter The synthesis of 5S ribosomal RNA (rRNA), or an equivalent rRNA, from a DNA template by RNA polymerase III (Pol III), originating at a type 1 RNA polymerase III promoter. 5S rRNA transcription