The spontaneous loss of amino groups from adenine in DNA results in hypoxanthine, an uncommon base, opposite thymine. What combination of proteins could repair such damage?a. nuclease, DNA polymerase, DNA ligaseb. telomerase, primase, DNA polymerasec. telomerase, helicase, single-strand binding proteind. DNA ligase, replication fork proteins, adenylyl cyclase
Verified step by step guidance
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Identify the type of DNA damage: The problem describes the deamination of adenine, which results in the formation of hypoxanthine. This is a type of base modification that needs repair.
Understand the repair mechanism: The repair of such base modifications typically involves a process called base excision repair (BER).
Determine the proteins involved in BER: Base excision repair involves several key proteins, including a nuclease to remove the damaged base, DNA polymerase to fill in the gap, and DNA ligase to seal the nick in the DNA backbone.
Match the proteins to the options: Look for the combination of proteins that includes a nuclease, DNA polymerase, and DNA ligase, as these are the proteins involved in the base excision repair process.
Select the correct answer: Based on the understanding of the repair mechanism and the proteins involved, choose the option that lists nuclease, DNA polymerase, and DNA ligase.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
DNA Repair Mechanisms
DNA repair mechanisms are essential processes that correct damage to the DNA molecule. They involve various proteins that recognize and fix alterations, such as base modifications or strand breaks. Understanding these mechanisms is crucial for identifying which proteins are involved in repairing specific types of DNA damage, such as the conversion of adenine to hypoxanthine.
Nucleases are enzymes that cleave the bonds between nucleotides in nucleic acids. They play a critical role in DNA repair by removing damaged or incorrect bases, allowing for the subsequent repair processes to take place. In the context of the question, nucleases would be necessary to excise hypoxanthine from the DNA strand before repair can occur.
DNA polymerase is an enzyme responsible for synthesizing new DNA strands by adding nucleotides complementary to the template strand. DNA ligase, on the other hand, seals the nicks in the sugar-phosphate backbone of DNA, ensuring the integrity of the newly synthesized strand. Together, these enzymes are vital for completing the repair process after damage has been recognized and excised.