BIO 330 Problem Set #2 Spring 2018 Temperature-sensitive or \'conditional\' muta
ID: 202721 • Letter: B
Question
BIO 330 Problem Set #2 Spring 2018 Temperature-sensitive or 'conditional' mutants are often used to study replication because it allows mutation which the mutation is activated is called the restrictive temperature. Such mutant strains can replicate temperature their DNA and be propagated at a lower temperature called the permissive ating naturally occurring temperature sensitive mutant strains of bacteria is often very helpful in figuring out the function of a particular protein. Determine the function of the following proteins baseo on the experiments outlined below a. Several temperature sensitive strains of E. coli were tested for DNA replication activity. In ore strain, gyrase was found to be affected when the temperature was raised above 37°C, but was ional at 37 C and lower. Do you expect cells would be viable if grown at clevated temperatures? Explain why/why not Several temperature-sensitive mutant strains of E coli are shown to exhibit the following characteristics. Based on your knowledge of DNA replication components, predict what enzyme(s) might be affected by each mutation. (Note: answers can be used more than once AND multiple answers may be used for each question) 2. No initiation occurs 3. Synthesis is very slow 4. Okazaki fragments accumulate and DNA synthesis is never completed 5. Newly synthesized DNA contains many mismatched bases 6. Supercoiled and entangled strands remain after replication which is never complete. a. DNA polymerase III b. Replication clamp c. Topoisomerase II d. Ligase e. DNA Polymerase I f. DnaB g RNase H h. DnaAExplanation / Answer
Cells will not grow above 37 as gyrase will be nonfunctional so the supercoiled DNA generated by helicase during replication will not be removed as a result replication will stop. if replication stops then cell division will stops and bacteria will not grow.
DNA polymerase III - newly synthesized DNA contains many mismatch base pair. Or no initiation occurs as the pre-replicative can't be formed.
Replication clamp - replication will be very slow
Topo isomerase II - supercoiled and entangled strand remain after replication which is never complete.
Ligase - okazaki fragments accumulate and DNA synthesis never completed.
DNA polymerase I - no initiation occurs
DnaB - no initiation occurs ( non functional helicase)
RNaseH - RNA primer will not be removed so newly synthesized DNA contains many mismatched base pair.
DnaA - no initiation occurs.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.