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 ligase b. telomerase, primase, DNA polymerase c. telomerase, helicase, single-strand binding protein d. DNA ligase, replication fork proteins, adenylyl cyclase

Verified step by step guidance

1. Identify the type of DNA damage described: The problem states that adenine loses an amino group to form hypoxanthine, which then pairs incorrectly with thymine. This type of damage is a form of deamination, which alters the base pairing in DNA.
2. Understand the repair mechanism needed: The repair of such damage generally involves base excision repair (BER). This process first requires the recognition and removal of the incorrect base, followed by the filling in of the correct base and sealing of the DNA backbone.
3. Analyze the options given: Option (a) lists nuclease, DNA polymerase, and DNA ligase. Nuclease can excise the damaged base, DNA polymerase can fill in the correct nucleotide, and DNA ligase can seal the phosphate backbone.
4. Eliminate other options: Option (b) includes telomerase and primase, which are not involved in DNA repair processes. Option (c) also includes telomerase, which is irrelevant for DNA repair. Option (d) includes DNA ligase but lacks the necessary enzymes for initial recognition and excision of the damaged base.
5. Conclude the correct answer: Based on the understanding of the base excision repair mechanism, the correct combination of proteins to repair the deamination of adenine to hypoxanthine is nuclease, DNA polymerase, and DNA ligase, which corresponds to option (a).