I have been given a DNA nucleotide sequence and have established the equivalent mRNA sequence.I have then been given 2 mutations and I have worked out the new mRNA sequence but I have to suggest why it may change the function of the new protein. The new sequence is AUA AGC UUU, and I know that the start codon is always AUG, but I'm not sure how it would change the function of the protein? Any help would be appreciated!
I thnk the answer would be that this mRNA would not be translated into a polypeptide chain?
Further on in the question it states that the mutation found is the change to produce the dominant gene for continued lacatse production throughout adult life. However, if AUG is always the start codon, the how would the new sequence be possible? If it's not translated into a polypeptide chain then what is it? I think I have missed something vital here!
I've come up with: Ile,Ser, Phe. Can this be done? if so how does it change the function of the protein?
I got the same. It says in bk 9 that a mutation in the DNA code can be transcribed into mRNA and subsequently translated into a protein on p130. It's also got some info on p127. I'm not too sure why it may change the function. I'm guessing the code is right, but if it's not a polypeptide chain then I don't know what it is! Great way to spend the easter holidays.
Based on the given information, let's break down the problem and address your questions.
1. You have a DNA sequence and its corresponding mRNA sequence: AUA AGC UUU.
2. You've identified two mutations but have not mentioned which specific nucleotides were changed.
3. You correctly noted that the start codon is always AUG, and the sequence you provided (AUA AGC UUU) does not contain the start codon.
Regarding your confusion about how the new sequence could change the function of the protein, let's clarify a few points:
1. The provided mRNA sequence (AUA AGC UUU) can still potentially be translated into a polypeptide chain. However, it will not start with the conventional start codon AUG, which might affect the initiation of translation.
2. Mutations in the DNA sequence can lead to changes in the mRNA and, subsequently, the protein sequence. These changes can alter the structure or function of the resulting protein.
3. Without detailed information about the specific mutations, it is challenging to determine exactly how the protein function may be affected.
To effectively suggest how the mutations could change the function of the protein, you need to identify and understand the nature and location of the mutations. This information will allow you to analyze potential alterations in the protein's amino acid sequence, structure, or function. Once you have determined the specific mutations, you can compare the resulting amino acid sequence with the original sequence and investigate the potential consequences.
Considering your statement "Ile, Ser, Phe," it appears that you have identified the corresponding amino acids for the new mRNA sequence AUA AGC UUU. However, without understanding the nature of the mutations, it is difficult to determine the precise impact on protein function.
To gain more insights, I recommend referring to the provided book pages (p130 and p127) for further information on DNA mutations and their effects on protein synthesis. Additionally, considering the context of "producing the dominant gene for continued lactase production throughout adult life," it would be helpful to review relevant sections to better understand the specific mutation's implications and potential changes in lactase expression or function.
Overall, it is crucial to analyze the specific mutations and compare the resulting protein sequence with the original sequence to make an informed suggestion about how the mutations may impact the function of the protein.