of the two possible pathways for an exogenous guanine source to reach dna , firstly : dguo -- -- dgmp -- -- dgdp -- -- dgtp and secondly : gua -- -- gmp -- -- gdp -- -- dgdp -- -- dgtp only the second pathway was found to be functional in providing guanine for dna replication , although deoxyguanosine readily produced toxic cellular dgtp levels via the first pathway .
C0012854
dna
C0598312
dna replication