Can anyone comment on my working out for the following question.
position - - 1 2 3 4 5 6 7 8 9 -
Nucleotide - - T A C T C G G A A -
Write down the equivalent mRNA and hence work out the sequence of amino acid names coded in this part in the polypeptide produced you can assume that postion 1 is start of the codon
I have converted this to
A T G A G C C T T
Then to m RNA
A U G A G C C U U
AUG Methionine (Met) or START
AGC Ser
CUU CUU Leucine (Leu)
Question asks you work out new sequence when following changes take place mutation of C to T in position 3 and another of G to A in position 7
so,
A T A A G C T T T
in m RNA
A U A A G C U U U
Which is,
AUA Ile
AGC Ser
UUU Phenylalanine (Phe)
question goes on to state work out new sequence as I think I have done ??
suggest why the changes may alter the function of the new protein ??
Im stuck here !!!
Input appreciated !
Thanks !!!
Initiation of the protein synthesis begin with first amino acid i.e methionine. Since mutant strand lack methionine there will be no protein synthesis.
If the mutation is somewhere within the coding region of this gene, then it will result in abnormal protein, because of the change in it secondary structure which is altered due to mutation, and it will results in protein which will not be able to bind the substrate or its half life if altered.
Thank you,
Is the coding correct please ??
Cheers
Yes, the initial coding you provided is correct. The equivalent mRNA sequence is indeed A U G A G C C U U.
In the second part, the mutation changes the nucleotide at position 3 from C to T and at position 7 from G to A. This results in the mRNA sequence A U A A G C U U U.
The sequence of amino acids coded in this mutated part of the polypeptide is AUA (Isoleucine), AGC (Serine), UUU (Phenylalanine).
Now, regarding the question of why these changes may alter the function of the new protein, it is important to note that amino acids play a critical role in determining the protein's structure, stability, and function.
In the case of a mutation like this, where one amino acid is substituted for another, it can lead to changes in the protein's three-dimensional structure. This can affect the protein's ability to interact with other molecules, such as substrates or other proteins, which may be necessary for its normal function.
Furthermore, the mutation at position 3 results in a change from methionine to isoleucine, which occurs at the beginning of the protein sequence. Methionine is often important for protein targeting and initiation, so this change at the start of the protein could impact its function from the very beginning.
Overall, these changes in the protein sequence due to the mutations can potentially result in altered protein function, which may interfere with its normal biological processes.