To infect T cells, M-tropic human immunodeficiency virus-1 (HIV-1) strains bind to the cell surface protein CCR5, which is normally a receptor for various immunity-related factors.About 10 percent of Scandinavians are heterozygous for a CCR5 allele with a 32-base-pair deletion that introduces a premature stop codon, thereby creating a protein that binds neither factors nor virus.Heterozygous individuals exhibit some resistance to M-tropic HIV-1 infection, and homozygous individuals are very resistant to infection.In the case of HIV-1, this _______ mutation has proven to be _______.

Question

Quizplus · Accepted Answer

The 32-base-pair deletion in CCR5 creates a loss-of-function mutation, meaning that the protein produced by this allele has reduced or eliminated function compared to the wild-type protein. This mutation has been shown to be beneficial in the context of M-tropic HIV-1 infection, as it confers resistance to the virus. Therefore, the best choice is D, loss-of-function; beneficial.

To Infect T Cells, M-Tropic Human Immunodeficiency Virus-1 (HIV-1) Strains