Transcription DNA consists of four nucleotide bases [adenine (A), guanine (G), cytosine (C), and thymine (T)] that are paired together (A-T and
C-G) to give DNA its double helical shape. Nucleotide base sequences are the genetic code or instructions for protein synthesis. During transcription, RNA polymerase binds to the DNA and seperates the DNA strands. RNA polymerasse then uses the one strand of DNA as atamplate from which nucleotides are assembled into a strand of RNA.The promoters signals in DNA cause transcription to stop when the new RNA molecule is completed.