Consider a single base substitution that creates α-globin gene mutant Hb Constant Spring (Hb CS ), whose product contains 172 amino acids. Wild-type α-globin protein contains 141 amino acids. The wild-type mRNA carries the codon CGU to encode arginine (Arg) as the final amino acid of the chain, followed by the stop codon UAA. The Hb CS mutant produces mRNA that has the sequence CGUCAA in this region. Using this information, explain how single DNA base substitution in Hb CS can lead to the production of a protein that contains 31 more amino acids than the wild type has. Introduction: The α-globin gene mutant Hb Constant Spring (Hb CS ) is created by a single base substitution mutation. Single base substitution is a type of mutation in which one base is substituted by another base (for example - switching of base U to A). Such mutation can produce a different type of peptide chain or can result in premature termination or increase in the length of the peptide chain. In case of Hb Constant Spring (Hb CS ), the protein chain produced by the mutant gene contains 172 amino acids. 31 amino acids are extra when compared to the wild type with 141 amino acids.

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Chapter 10, Problem 7P

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Consider a single base substitution that creates α-globin gene mutant Hb Constant Spring (Hb^CS), whose product contains 172 amino acids. Wild-type α-globin protein contains 141 amino acids. The wild-type mRNA carries the codon CGU to encode arginine (Arg) as the final amino acid of the chain, followed by the stop codon UAA. The Hb^CS mutant produces mRNA that has the sequence CGUCAA in this region. Using this information, explain how single DNA base substitution in Hb^CS can lead to the production of a protein that contains 31 more amino acids than the wild type has.

Introduction:

The α-globin gene mutant Hb Constant Spring (Hb^CS) is created by a single base substitution mutation. Single base substitution is a type of mutation in which one base is substituted by another base (for example - switching of base U to A). Such mutation can produce a different type of peptide chain or can result in premature termination or increase in the length of the peptide chain. In case of Hb Constant Spring (Hb^CS), the protein chain produced by the mutant gene contains 172 amino acids. 31 amino acids are extra when compared to the wild type with 141 amino acids.

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