Question

One cause of the neurodegenerative disease amyotropic, lateral sclerosis (ALS) is the expansion of the repeating hexanucleotide sequence GGGGCC in the noncoding region of a gene. By unknown mechanisms, the repeating sequence is translated to generate neurotoxic peptides. Predict the sequences of the possible repeating dipeptides.

Short answer

The possible repeating dipeptides are GGG-GCC, GGC-CGG and GGG-CCG.

Step-by-step solution

Amyotropic lateral sclerosis

Amyotropic lateral sclerosis(ALS) is also known by another name motor neuron disease ( MND). It leads to the deprivation of motor neurons that regulates the voluntary muscles.

Predicting the sequence of the possible repeating dipeptides.

During the translation process, the repeating sequence is converted into neurotoxic peptides. The possible repeating dipeptides are GGG-GCC, GGC-CGG and GGG-CCG. The dipeptide GGG-GCC codes for Gly-Ala, GGC—CGG codes for Gly-Arg and GGG-CCG codes for Gly-Pro. Hence, the sequences for the possible repeating dipeptides are obtained.