Biotechnology and Bioinformatics (1+1)

1.4.8.2. Elongation

RNA polymerase assembles bases that are complimentary to the DNA strand being copied. RNA contains uracil instead of thymine. Once the RNA polymerase has synthesized a short stretch of RNA (approximately ten bases), it shifts into the elongation phase. During elongation, the enzyme performs an impressive range of tasks in addition to the catalysis of RNA synthesis. It unwinds the DNA in front and re-anneals it behind, it dissociates the growing RNA chain from the template as it moves along, and it performs proofreading functions.