Assertion: purine | /r/CapableOf | take the place of thymine
Facets:
value: in rna
type: LOCATION
value: usually
type: TEMPORAL
Source sentences:
text: the purines, A and G, which are fused five- and six-membered heterocyclic compounds, and the pyrimidines, the six-membered rings C and T. A fifth pyrimidine nucleobase, uracil (U), usually takes the place of thymine in RNA and differs from thymine by lacking a methyl group on its ring.