This invention relates to nucleotide analogs and their derivatives (termed non-standard nucleotides) that, when incorporated into DNA and RNA, expand the number of nucleotides beyond the four found in standard DNA and RNA. The invention further relates to enzymatic processes that incorporate those non-standard nucleotide analogs into oligonucleotide products using the corresponding triphosphate derivatives. The RNA polymerases of the instant invention transcribe DNA containing nonstandard nucleotides to give RNA containing nonstandard nucleotides, where certain of those nucleotides have nucleobases that do not present electron density to the minor groove.