Question
Biology Question on the molecular basis of inheritance
Which of the following are initiator codons ?
A
UGA and UAG
B
UAC and UAG
C
AUG and GUG
D
UAA and UAG
Answer
AUG and GUG
Explanation
Solution
In most cases the initiating codon is AUG, which otherwise codes for methionine. The corresponding codon on mRNA is usually AUG, but rarely it could be GUG also. When GUG is used as the initiating codon, it does not code valine, but initiating methionine molecule should be found in the formylated methionine.