Genetics: Analysis and Principles 5th Edition by Robert Brooker

Exercise 27

coli, a methyltransferase enzyme encoded by the dam gene recognizes the sequence 5 -GATC-3 and attaches a methyl group to the N 6 position of adenine. E. coli strains that have the dam gene deleted are known to have a higher spontaneous mutation rate than normal strains. Explain why.