Given the DNA sequence TACCGCTCCGCCGTCGACAATACCACT, what are the corresponding mRNA codons, tRNA anticodons, and amino acid (AA) sequence?

What you are being asked to do

You are converting a DNA sequence into three things in order: the mRNA produced by transcription, the tRNA anticodons that pair with that mRNA, and the amino acids made during translation.

Transcribe the DNA into mRNA

Because the DNA starts with $TAC$, it is typically the template strand, which transcribes to the start codon $AUG$.

1. Split DNA into codons:

DNA: $TAC\ CGC\ TCC\ GCC\ GTC\ GAC\ AAT\ ACC\ ACT$

2. Make the complementary mRNA using base-pair rules (DNA $T\to$ RNA $A$, DNA $A\to$ RNA $U$, $C\leftrightarrow G$):

mRNA: $AUG\ GCG\ AGG\ CGG\ CAG\ CUG\ UUA\ UGG\ UGA$

Find the tRNA anticodons

tRNA anticodons are complementary to the mRNA codons:

$$ \begin{array}{l} AUG\to UAC\\ GCG\to CGC\\ AGG\to UCC\\ CGG\to GCC\\ CAG\to GUC\\ CUG\to GAC\\ UUA\to AAU\\ UGG\to ACC\\ UGA\to \text{STOP (no tRNA)} \end{array} $$

So the anticodons are: $UAC\ CGC\ UCC\ GCC\ GUC\ GAC\ AAU\ ACC$.

Translate mRNA codons into amino acids

Use the genetic code:

• $AUG$ = Met (start)
• $GCG$ = Ala
• $AGG$ = Arg
• $CGG$ = Arg
• $CAG$ = Gln
• $CUG$ = Leu
• $UUA$ = Leu
• $UGG$ = Trp
• $UGA$ = Stop

Amino acids: Met–Ala–Arg–Arg–Gln–Leu–Leu–Trp–Stop.