In: Biology
Given the DNA strand, 3’ TTG-TAA-CGC-CAT-ATG-GAC-AGC 5’, what is the resulting
amino acid sequence of this polypeptide?
. What tRNA anti codon would bind to each mRNA codon in the last part? Draw how this works by
drawing the mRNA interacting with the tRNA in the ribosome.
Ans
If the DNA strand is 3' TTG-TAA-CGC-CAT-ATG-GAC-AGC 5', the resulting mRNA is 5' AAC-AUU-GCG-GUA-UAC-CUG-UCG3' because mRNA is synthesized from template strand and its sequence is complementary to mRNA. The polypeptide synthesized from this mRNA is asn-ile-ala-val-tyr-leu-ser because AAC codes for asparagine, AUU for isoleucine, GCG for alanine, GUA for valine, UAC for tyrosine, CUG for leucine and UCG for serine.
According to wobble hypothesis, the third base of mRNA is wobble base. If the U is present in third position of mRNA codon, it cans pairs with A or G in the first position of tRNA anticodon. So, if the mRNA sequence is 5'AUU3', the tRNA anticodon sequences are either 5'AAU3' or 5'GAU3'. The resulting tRNA anticodon sequences from each mRNA codon is given below-
The drawing of mRNA interaction with tRNA is given below-