What is DNA Template Strand?
A DNA template strand generally refers to the strand which is used by the enzyme DNA polymerases and RNA polymerases to attach with the complementary bases during the process of replication of DNA or at the time of transcription of RNA respectively.
In such cases, wither the molecule moves down towards the strand in the direction of 3’ to 5’ end and at each of the subsequent bases, it adds a complement to the current base of the DNA to the growth of nucleic acid strand which is being created by the 5’ to 3’ end.
The new strand created by the complementary, it matches the opposing strands of the DNA, which is known as coding strand.
Features of DNA Template Strand
Template strand in the DNA is also known as anti-sense strand; which is one of strand in the DNA that is present after they are being unwounded by the enzyme DNA helicase while the process of transcription.
Ribonucleotide triphosphates align themselves along the anti-sense strands by the base pairing made by Watson-crick.
In eukaryotes the ribonucleotides are further joined by the RNA polymerases II. Where as in prokaryotes the pre-mRNA, which is complementary to the template strand.
Transcription ends when the RNA polymerases reach the stop coding. In eukaryotes splicing takes place in order to remove the non-coding regions of the DNA to gives the final mRNA strand.
Then further the mRNA strand leaves the nucleus through the nuclear pore and is then translated by the ribosome, which is one of the cell organelles to form a sequence of amino acids Ans forms a necessary protein.
Characteristic DNA Template Strand
Template strand consists of an anticodon. It contains the same nucleotide sequences as such of the tRNA. Where the codon and template strand are the two different strands of the double strand DNA.
The template strand acts as a base for transcribing the mRNA and the others determines the appropriate base sequence for the mRNA.
It actually acts as a template for the synthesis of RNA. It moves in a direction of 3’ to 5’.
The RNA polymerases read the template strand in the direction of 3’ – 5’ end. It has a nucleotide base sequence which is complementary to both the coding strands and also to the mRNA.
During genetic coding the template strands have the anticodons. During the formation of hydrogen bonds, the bonds formed in the template strands are temporary and whereas the newly synthesised mRNA occurs at the time of transcription.
Function of DNA Template Strand
As said before template strand is one of the DNA strands whose sequence of bases helps in building up the mRNA through the complementary base sequencing.
Template strand which is also known as antisense strands runs in the direction of 3’ to 5’ ends, which runs opposite to the coding strands.
Template strand contains the complementary nucleotide sequences which are further transcribes into the m-RNA.
After the process of transcription, the mRNA is converted into the mature mRNA, which undergoes specific post-transcriptional modifications.
The template strand also contains the anticodons which carries the triplet codes or the triplet nucleotide sequences complementary to anticodon sequence of a t-RNA.
The anticodon thus helps in attaching the specific amino acid to the t-RNA and forms proteins or a polypeptide chain through the assistance of the r-RNA.
An enzyme RNA polymerase reads the template strand to synthesis the RNA transcript by recognising the specific sequences.
Hence, RNA polymerase is considered as the one which decides the initiation of the transcription and also in the termination of the translation process.
Coding DNA Template Strand
Template and coding strands are the terms generally used to describe the strands which are present in the DNA. During the process of transcription, one of the two strands in the double stranded DNA serves as a template strand.
This template strand walks in the direction of 3’ to 5’ end. Where as the other strand which is present in the DNA, other than the template strand is known as coding strand.
Template strand is responsible for the sequencing amino acid for synthezing the polypeptide chain.
The main difference to be considered between the coding and template strand is that the template strand serves as the template for the transcription where the coding strand contains the exact and the same sequence of the nucleotides in mRNA, expect the nucleotide thymine.
DNA Template Strand and Transcription
A single strand of RNA is synthesised using a double stranded DNA molecule as the template. The two strands of the molecule of DNA are separated from one another by exposing the nitrogenous bases.
Only one of the strands is actively used as a template in the process of transcription. The strand which is used as a template is also known as template strand or sense strand.
The complementary strand of the DNA is the one which is not used and is called as the nonsense strand or the antisense strand.
The RNA sequence which is made up of a direct copy of the nitrogenous bases in the template strand.
If Guanine base is a part of sequence on the template DNA strand, then the molecule of RNA has a Cytosine base which is added to its sequence at that point.
In the molecule of RNA, uracil substitutes for Thymine.
DNA Template Strand Citations
- Probing DNA polymerase-DNA interactions: examining the template strand in exonuclease complexes using 2-aminopurine fluorescence and acrylamide quenching. Biochemistry . 2007 Jun 5;46(22):6559-69.
- Detection of template strand switching during initiation and termination of DNA replication of porcine circovirus. J Virol . 2004 Apr;78(8):4268-77.
- DNA template-assisted inhibition of tyrosinase activity. Int J Biol Macromol . 2015 Aug;79:278-83.