Nontemplate strand

Definition

The nontemplate strand, also known as the coding strand, is the DNA strand whose sequence matches the RNA transcript produced during transcription. It is complementary to the template strand used by RNA polymerase for synthesis of mRNA.

5 Must Know Facts For Your Next Test

1. The nontemplate strand has the same nucleotide sequence as the mRNA (except thymine is replaced by uracil in RNA).
2. During transcription in prokaryotes, RNA polymerase reads the template strand but produces an RNA copy that mirrors the nontemplate strand.
3. It is called the coding strand because its sequence directly corresponds to the codons in mRNA that are translated into protein.
4. The direction of transcription (5’ to 3’) on the nontemplate strand runs parallel to the direction of RNA synthesis.
5. The sequence of bases in the nontemplate strand determines which amino acids will be added during translation to form a protein.

Review Questions

• What is another name for the nontemplate strand?
• How does the nucleotide sequence of the nontemplate strand compare to that of mRNA?
• Why is it called the coding strand?

Related terms

templateStrand: The DNA strand that serves as a guide for RNA polymerase during transcription.

mRNA: Messenger RNA; a type of RNA that conveys genetic information from DNA to ribosomes for protein synthesis.

transcription: The process where an RNA molecule is synthesized from a DNA template.