Final answer:
A deletion mutation that does not occur in multiples of three leads to a frameshift mutation, changing every subsequent codon, potentially leading to significant alterations in protein structure and function, such as creating nonfunctional proteins or terminating protein synthesis.
Step-by-step explanation:
When discussing the effects of a deletion mutation on an amino acid chain, it's important to understand how this mutation alters the resulting protein. The deletion of a single nucleotide from the DNA sequence can lead to a frameshift mutation. This mutation shifts the reading frame, changing every codon that follows the point of mutation. An original sequence coding for the polypeptide met-lys-phe-gly-ile-val-pro, when missing a U from the third position of the third codon, results in a shortened and altered polypeptide met-lys-leu-ala due to the change in subsequent codons and the introduction of a premature stop codon.
Problems arise because the genetic code is read in triplets, or codons. Deletions that do not occur in multiples of three are particularly problematic as they change the rest of the sequence dramatically. This can lead to significant changes in the protein structure and function, such as creating nonfunctional proteins or terminating protein synthesis entirely. For example, the deletion mutation associated with cystic fibrosis results from the loss of three nucleotides which causes the loss of amino acid phenylalanine in the protein involved.