The p53 gene is an important tumor suppressor gene in our genome. It codes for a transcription regulatory protein that can assemble into tetramers. A number of mutations in p53 render the protein inactive. These mutant protein molecules form mixed tetramers with wild-type p53 proteins and, in this case, the tetramer is inactive. The mutations can therefore be categorized as …
A) null.
B) gain-of-function.
C) recessive lethal.
D) dominant-negative.
E) suppressor.

Question

Quizplus · Accepted Answer

These p53 mutations are dominant-negative because they cause a loss-of-function phenotype even in the presence of a normal copy of the gene. This phenomenon occurs when the mutant gene product interferes with the function of the normal gene product.

The P53 Gene Is an Important Tumor Suppressor Gene in Our