Like most cellular processes, transcription is directed by the action of –

Like most cellular processes transcription is directed by the action of RNA Polymerase enzyme.

Explanation:

RNA Polymerase is a complex enzyme that bind to specific nucleotide sequence of the sense strand of the target DNA called promoter to initiate the process of transcription.

          There are many promoter region in both prokaryotic ans eukaryotic DNA such as TATA Box, Pribnow box for Prokaryotes and GC  Box, CAAT Box for eukaryotes.

           These promoter regions are the main binding site of RNA ploymerase ,after binding to the the promoter site RNA polymerase moves moves along the template DNA strand thus making mRNA in 5prime to 3prime direction.