Which protein is most likely to be impaired in their mutant bacteria in the following situation? You are studying a strain of bacteria that carries a temperature-sensitive mutation in one of the genes required for DNA replication. The bacteria grow normally at the lower temperature, but when the temperature is raised they die. When you analyze the remains of the bacterial cells grown at the higher temperature you find evidence of partly replicated DNA. When the strands of this DNA are separated by heating, numerous single-stranded DNA molecules around 1000 nucleotides long are found.
A. DNA polymerase B. Ligase C. Helicase D. Primase E. Single stranded binding
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A. LuciusSenior Content writer, Diploma in Literature, Dover, Delaware
Senior Content writer, Diploma in Literature, Dover, Delaware
Answered on Nov 01, 2019
The correct answer is option B – Ligase. The enzyme that is mutant in the bacteria is ligase. Ligase is an enzyme that functions to join large molecules to form chemical bonds between them. Since the DNA molecules discovered after heating are numerous single-stranded DNA molecules, around 1000 nucleotides are found, it shows that the function of ligase is not present in the bacteria.
Option A is incorrect because DNA polymerase functions in DNA replication to synthesize new DNA. Option C is incorrect because helicase is an enzyme that functions to unwind DNA strands to begin the process of DNA replication. Option E is incorrect single-strand DNA binding is a protein that binds to the single strand regions of the DNA to maintain DNA metabolisms such as DNA replication, recombination, and DNA repair.