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Diagram illustrating the structure and function of the human p53 protein, showing its ribbon structure bound to DNA, detailed views of its primary and secondary structures, and a color-coded map of its domains along the amino acid sequence.
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p53

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Diagram illustrating the structure and function of the human p53 protein, showing its ribbon structure bound to DNA, detailed views of its primary and secondary structures, and a color-coded map of its domains along the amino acid sequence.
p53 protein The p53 protein prevents cells with damaged DNA from dividing or, when damage is too great, promotes cell death. The primary structure of the protein is the sequence of amino acids linked together in a polypeptide chain; groups of amino acids, called domains, have specific functions, such as the binding of DNA. Hydrogen bonding between polypeptide chains of the protein forms beta-pleated sheets, the primary component of the secondary structure. The ribbonlike tertiary structure is a result of yet further folding to form the overall structure of the p53 protein; a zinc atom located between two amino acid loops stabilizes the protein's binding to DNA.

The p53 gene produces a protein that acts as a tumor suppressor. This protein plays a crucial role in regulating cell proliferation and preventing cells with damaged DNA from dividing. If DNA damage is too extensive, the p53 protein can trigger programmed cell death, known as apoptosis.12

When the p53 gene is inactivated, often through mutation, this critical control mechanism is lost. This allows damaged cells to divide and accumulate genetic errors, significantly increasing the risk of developing various cancers, including colon, breast, and lung cancer. The mutated p53 protein is implicated in over half of all human cancers.23

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3 Britannica Sources
  1. p53
  2. cancer - The p53 gene
  3. tumor suppressor gene: Top Questions

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