THE DEFINITIVE GUIDE TO POS88

to review the effect of many constraints on mutational tolerance through range, we selected E. coli dihydrofolate reductase (DHFR) as a product procedure. DHFR is an essential enzyme in just folate metabolism that lessens dihydrofolate to tetrahydrofolate and is also essential for thymidine output. utilizing this activity as The idea for an in vivo