DEOXYRIBONUCLEOTIDE-CONTAINING RNAS - A NOVEL CLASS OF TEMPLATES FOR HIV-1 REVERSE-TRANSCRIPTASE

Deoxyribonucleotide-containing RNA-like polynucleotides (dcRNAs) were synthesized by mutant T7 RNA polymerase and their structures confirmed by sequencing. dcRNAs annealed with a 20mer oligodeoxyribonucleotide primer were tested as templates/primers in the reverse transcription r eaction catalyzed by HIV-1 reverse transcriptase (RT). All dcRNAs were shown to be efficient templates for both wild-type RT and RT mutants, containing 'AZT-resistant' mutations. Differences in the patterns of the DNA products of RNA-and dcRNA-driven reverse transcription were de monstrated. The kinetic characteristics for dcRNAs utilization were co mpared with the corresponding parameters for RNA/DNA and DNA/DNA templ ates/primers. The respective K-m values for dcRNAs appear to be interm ediate between those for RNA and DNA templates. A correlation equation connecting apparent K-m value for template/primer and the number of d eoxyribonucleotide substitutions in RNA template is proposed.