because the g : c-t : a and a : t-t : a transversions can either result from the insertion of an adenine across from apurinic sites or arise due to the incorporation of syn-adenine opposite a purine base , we postulate that the dna polymerase iii holoenzyme also has a reduced discrimination ability in a dnaq49 background .
C0001407
adenine
C0034140
purine