Question

Nonsynonymous mutations in genes are nucleotide changes that alter the amino acid sequence of the translated protein, potentially leading to a change in protein function. Using your knowledge of the genetic code, which ONE of the following amino acid replacements can be caused by a single-base change?

Select one:

a. Val → Lys

b. Asp → Thr

c. Pro → Val

d. Gly → Leu

e. Cys → Phe

Answer 1

(e) Cysteine---> Phenylalanine

Nonsynonymous mutations are defined as the mutations in which a single base change result in the alteration of codon which leads to translation of a different amino acid from that of wild-type and hence the altered protein structure.

For eg. Cysteine is coded by triplet

UGC, and UGU in which a single base change from G to U results in formation of phenylalanine coded by UUC and UUU

a) Valine Thr Lysine -> b ) АСА AAA GUU GUC GUA Asp GAU GAC AAG ACC Ac6 ACU GUG deucine Valine c) Proline d) Glycine UUA CCA GUA GUC (ეფ) GGC UG Coc CUU CCG CCU GUG GUU GGG GGU CUC CUA CUG be el cysteine Phenylalanine U uc GU @c UGU UUU Gau single base change