Concept explainers
To review:
The sequence of the following synthetic mRNA:
5’-AUG UCU CCU ACU GCU GAC GAG GGA AGG AGG UGG CUU AUC AUG UUU-3’
The type and effect of mutation in the following polypeptide products:
a. 5’-AUG UCU CCU ACU UGC UGA CGA GGG AAG GAG GUG GCU UAU CAU GUU U-3’
b. 5’-AUG UCU CCU ACU GCU GAC GAG GGA GGA GGU GGC UUA UCA UGU UU-3’
c. 5’-AUG UCU CCU ACU GCU GAC GAG GGA AGG AGG UGG CCC UUA UCA UGU UU-3’
d. 5’AUG UCU CCU ACU UGC UGA CGG AAG GAG GUG GCU UAU CAU GUU U-3’
Introduction:
Frameshift mutations result from the addition or deletion of one or a few base pairs within the reading frame. They alter the reading frame of all the base pair triplets present after the mutation site and hence are aptly named.
Explanation of Solution
Proteins are macromolecules, which are formed of one or more amino acid chains. Proteins are formed by the bond between two amino acids known as the amide bond or the peptide bond. The primary structure of a protein is an amino acid sequence. Three nucleotides in a reading frame are known as a codon. One codon codes for only one amino acid.
So, the sequence of a polypeptide coding
5’-AUG UCU CCU ACU GCU GAC GAG GGA AGG AGG UGG CUU AUC AUG UUU-3’
will be as follows:
5’-Met-Ser-Pro-Thr-Ala-Asp-Glu-Gly-Arg-Arg-Trp-Leu-Ile-Met-Phe-3’
a. Type of mutation in 5’-AUG UCU CCU ACU UGC UGA CGA GGG AAG GAG GUG GCU UAU CAU GUU U-3’: It is a type of deletion mutation, as the G
5’-Met-Ser-Pro-Thr-Cys-3’
b. Type and effect of a mutation in 5’-AUG UCU CCU ACU GCU GAC GAG GGA GGA GGU GGC UUA UCA UGU UU-3’: This is a type of insertion mutation, as two G residues are introduced after GGA codons in the original peptide. The new amino acid sequence will be as follows:
5’-Met-Ser-Pro-Thr-Ala-Asp-Glu-Gly-Gly-Gly-Leu-Ser-Cys-Phe or Leu-3’
In place of Arg amino acid, glycine is present, which is a non-sense mutation. The rest of the polypeptide sequence is also changed.
c. Type and effect of a mutation in 5’-AUG UCU CCU ACU GCU GAC GAG GGA AGG AGG UGG CCC UUA UCA UGU UU-3’: In place of U in the 11th codon, there is A, which is a transition mutation. The new amino acid sequence will be as follows:
5’-Met-Ser-Pro-Thr-Ala-Asp-Glu-Gly-Arg-Arg-Trp-Pro-Leu-Ser-Cys-Phe or Leu-3’
d. Type and effect of mutation in5’AUG UCU CCU ACU UGC UGA CGG AAG GAG GUG GCU UAU CAU GUU U-3’: In this peptide, U is inserted in 5 codons at first place, which leads to a change in the sequence of the polypeptide. In this polypeptide, the sixth codon is a stop codon. So, the peptide will be terminated pre-maturely. The sequence of this peptide will be as follows:
5’-Met-Ser-Pro-Thr-Cys-3’
Thus, it can be concluded that in the first peptide, there is a G nucleotide in the fifth codon, which leads to the introduction of the stop codon (UGA). In the second peptide, there is an insertion mutation. In the third peptide, there is a transition mutation. In the last peptide, there is an insertion of U in the 5th codon. This forms a stop codon.
Want to see more full solutions like this?
Chapter 19 Solutions
Biochemistry: The Molecular Basis of Life
- A polypeptide has the following amino acid sequence: Met-Ser-Pro-Arg-Leu-Glu-Gly The amino acid sequence of this polypeptide was determined in a series of mutants listed in parts a through e. indicate the type of mutation that occurred in the DNA (single-base substitution, insertion, deletion) and the phenotypic effect of the mutation (nonsense mutation, missense mutation, frameshift, etc.). a. MMutant 4: Met-Ser-Pro-Glu-Glarrow_forwardA polypeptide has the following amino acid sequence: Met-Ser-Pro-Arg-Leu-Glu-Gly The amino acid sequence of this polypeptide was determined in a series of mutants listed in parts a through e. indicate the type of mutation that occurred in the DNA (single-base substitution, insertion, deletion) and the phenotypic effect of the mutation (nonsense mutation, missense mutation, frameshift, etc.). a. Mutant 5: Met-Ser-Pro-Arg-Leu-Leu-Glu-Glyarrow_forwardA polypeptide has the following amino acid sequence: Met-Ser-Pro-Arg-Leu-Glu-Gly The amino acid sequence of this polypeptide was determined in a series of mutants listed in parts a through e. indicate the type of mutation that occurred in the DNA (single-base substitution, insertion, deletion) and the phenotypic effect of the mutation (nonsense mutation, missense mutation, frameshift, etc.). a. Mutant 2: Met-Ser-Proarrow_forward
- A polypeptide has the following amino acid sequence: Met-Ser-Pro-Arg-Leu-Glu-Gly The amino acid sequence of this polypeptide was determined in a series of mutants listed in parts a through e. indicate the type of mutation that occurred in the DNA (single-base substitution, insertion, deletion) and the phenotypic effect of the mutation (nonsense mutation, missense mutation, frameshift, etc.). a. Mutant 1: Met-Ser-Ser-Arg-Leu-Glu-Glyarrow_forwardThe following four mutations have been discovered in a gene that has more than 60 exons and encodes a very large protein of 2532 amino acids. Indicate which mutation would likely cause a detectable change in the size of the mRNA and/or the size of the protein product. Consider a detectable change to be >10% of the wild-type size. A table of the genetic code is shown below. First letter 0 00 U O A บบบ UUC UUA UUG U CUU CUC CUA CUG Phe GUU GUC GUA GUG Leu >Leu AUU AUC lle AUA AUG Met >Val UCU UCC UCA UCG CCU CCC CCA CCG ACU ACC ACA ACG GCU GCC GCA GCG Second letter C Ser Pro Thr Ala CAU CAC CAA CAG UAU UGU Tyr UAC UGC UAA Stop UGA UAG Stop UGG AAU AAC AAA AAG A GAU GAC GAA GAG His Gin Asn Lys Asp G Glu CGU CGC CGA CGGJ AGU AGC AGA AGG GGU GGC GGA GGG O AAG576UAG (changes codon 576 from AAG to UAG) Cys Stop Trp O GUG326AUG (changes codon 326 from GUG to AUG) Arg Ser Arg Gly DUAG DUA G DCAG DO AG deletion of codon 779 insertion of 1000 base pairs into the sixth intron (this particular…arrow_forwardA wildtype gene produces the polypeptide sequence: Wildtype: Met-Ser-Pro-Arg-Leu-Glu-Gly Each of the following polypeptide sequences is the result of a single mutation. Identify the most likely type of mutation causing each, be as specific as possible. M1:Met-Ser-Ser-Arg-Leu-Glu-Gly missense mutation M2:Met-Ser-Pro M3:Met-Ser-Pro-Asp-Trp-Arg-Asp-Lys M4:Met-Ser-Pro-Glu-Gly nonsense mutation frameshift insertion in frame deletion M5:Met-Ser-Pro-Arg-Leu-Glu-Gly in frame insertionarrow_forward
- Consider the following DNA sequence, which codes for a short polypeptide: 5'-ATGGGCTTAGCGTAGGTTAGT-3' Determine the mRNA transcript of this sequence. You have to write these sequences from the 5' end to the 3' end and indicate those ends as shown in the original sequence in order to get the full mark. How many amino acids will make up this polypeptide? Determine the first four anticodons that will be used in order to translate this sequence.arrow_forwardGiven the following Wild Type and Mutated DNA sequences: 1.) Identify where the base pair change occurs ( what letter changed?) 2.) For BOTH sequences, write the mRNA strands, define the codon regions and amino acid sequences. 3.) Describe what kind of mutation has occurred (missense, nonsense, or silent), and what effect this may have on the protein. Wild Type DNA Sequence: 3' - AGGCTCGCCTGT - 5' Mutated DNA Sequence: 3' - AGTCTCGCCTGT - 5'arrow_forwardConsider the following original coding sequence of a gene that codes for a short 5- amino acid polypeptide: 5'-ATGGGCTCGAACTCATAA-3' Using the genetic code and the amino acid table below, which of the following sequences arises from a non-conservative missense mutation in the original sequence shown above? First base in codon U U A UUU UUC- UUA UUG- CUU CUC CUA CUG- U Phe (F) Leu (L) Leu (L) Second base in codon Val (V) UCU - UCC UCA UCG CCU CCC CCA CCG AUU ACU- AUC Ile (1) ACC AUA- ACA AUG Met (M) start ACG GUU GCU- GUC GCC GUA GCA GUG GCG- C Ser (S) Pro (P) Thr (T) Ala (A) UAU UAC UAAT UAG CAU CAC CAA CAG AAU AAC AAA AAG GAU GAC GAA GAG A Tyr (Y) STOP His (H) Gln (Q) Asn (N) Lys (K) Asp (D) Glu (E) G UGU UGC UGA STOP UGG Trp (W) Cys (C) CGU CGC CGA CGG AGU AGC AGA 1 AGG GGU- GGC GGA GGG Arg (R) Ser (S) Arg (R) Gly (G) U C A G U C A G U C A G U C A G Last base in codonarrow_forward
- Using the genetic code table provided below, write out the sequence of three different possible mRNA sequences that could encode the following sequence of amino acids: Met-Phe-Cys-Trp-Glu C A G U C UUU Phe UCU Ser UUC Phe UCC Ser UCA Ser UUA Leu UUG Leu UCG Ser CUU Leu CCU Pro CUC Leu CUA Leu CUG Leu CCG A CAU His CGU Arg CCC Pro CAC His CGC Arg UAU Tyr UGU Cys U UAC Tyr UGC Cys C Stop UGA Stop Stop UGG Trp UAA A UAG G CCA Pro CAA Gln Pro CAG AUU lle AUC lle AUA lle AUG Met ACG G 등등 Gln CGA Arg CGG Arg ACU Thr AAU Asn AGU Ser ACC AAC Asn AGC Ser Thr ACA Thr Thr AAA Lys AGA Arg AAG Lys AGG Arg GUU Val GCU Ala GAU Asp GGU Gly GGC Gly GUC Val GCC Ala GAC Asp GUA Val GCA Ala GAA Glu GGA Gly GUG Val GCG Ala GAG Glu GGG Gly U C A G U C A G SUAUarrow_forwardHuman wildtype and mutant alleles are identical in sequence except for a single base-pair substitution that changes one nucleotide towards the end of intron 2. The wildtype and mutant sequences of the affected portion of the mRNA are listed in the following table. Explain how a single base substitution could alter the reading frame, which could result in a physiological disorder?arrow_forwardWhich of the following mutations in the protein-coding region of a gene is more likely to lead to complete loss of function of the encoded protein: an insertion of six nucleotides or a deletion of two nucleotides? Briefly explain your answer.arrow_forward
- Biology (MindTap Course List)BiologyISBN:9781337392938Author:Eldra Solomon, Charles Martin, Diana W. Martin, Linda R. BergPublisher:Cengage Learning