In: Biology
The following is a portion of the non-template DNA sequence from the human ras gene. Answer the following questions about this gene and the effects of gene changes to the specified mutant sequence (mutation in BOLD).
Normal human ras: 5’-acatgactgaatataaacttgtggtagttggagctggt-3’
Mutant human ras: 5’-acatgactgaacataaacttgtggtagttggagctggt-3’
a. (4) What is the normal human Ras amino acid sequence from this portion of the gene, starting with the first start codon?
b. (2) Which amino acid from the normal sequence is mutated, and what is the amino acid changed to in the mutant sequence?
c. (3) What type of mutation is present in this gene (nonsense, missense, silent, transition, transversion)? Include all of the listed terms that apply.
d. (1) Is ras a proto-oncogene or a tumor suppressor gene?
e. (3) Describe the normal cellular function of Ras. How might a mutation in ras promote cancer formation, based on this normal cellular function described in your textbook?
a.mRNA seq: UGU ACU GAC UUA UAU UUG AAC ACC AUC AAC CUC GAC CA
Ptn seq : CYS THR ASP LEU TYR LEU ASN THR ILE ASN LEU ASP CA
b.Mutated Ptn: CYS THR ASP LEU TYR LEU ASN THR ILE ASN LEU ASP CA (AAT - AAC -----> Leucine) (T --->C pyrimidine to pyrimidine transition)
c. Silent Mutation: since there is no change in the amino acid change in the 2nd protein sequence
d. Ras is a proto - oncogene.
e.