How can I find the mRNA compliment of a DNA strand?
To get mRNA from DNA sequence: Reverse the DNA = TCCGGAATCGCCCTAG Convert into its complement = AGGCCTTAGCGGGATG Substitue U for T = AGGCCUUAGCGGGAUG When a DNA sequence is written as a single strand, it is ALWAYS the coding sequence that is given. When mRNA is made from the DNA, it makes the complement to this sequence –substituting U for T, as you already know. The trick is that the mRNA is transcribed in the 3′ to 5′ direction because it is temporarily bound to the DNA. Just like the complementary DNA would be written in the 3′ to 5′ direction, so is the RNA. In order to then write the mRNA sequence in the canonical 5′ to 3′ direction, the sequence needs to be written in reverse. I hope that helps!
