Guanine homo base pairs

As in the homo-base pair series, most hetero-base pair associations involve two hydrogen bonds. Only the Watson-Crick G-C base pair and two guanine-uracil pairs of no biological importance form three hydrogen bonds. In the following, we summarize the possible base-base combinations in matrix notation, with those possible with nucleic acids [where pyrimidine N(l) and purine N(9) are substituted] indicated in italic letters, as before. 

In Homo-DNA adenine and guanine pair strongly with themselves the base pairing selectivities in Homo-DNA are different from those operating in DNA. 

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