DNA-hybridization electron microscopy. Localization of five regions of 16 S rRNA on the surface of 30 S ribosomal subunits.

DNA-hybridization electron microscopy has been used to locate five regions of 16 S rRNA on the surface of 30 S ribosomal subunits. Biotinylated DNA probes that are complementary to selected regions of 16 S rRNA were hybridized to activated 30 S ribosomal subunits. These hybridized probes were reacted with avidin and localized by electron microscopy. The specificity of DNA binding was monitored with RNase H, which recognizes RNA-DNA hybrids and cleaves the RNA. Three of the five sequences examined were mapped on the platform. These sequences are 686-703, 714-733 and 787-803. Region 1492-1505 is mapped in the cleft and region 518-533 is at the neck on the side opposite the platform, respectively.