Ornithine Decarboxylase Antizyme Pseudoknot RNA Binding to Spermine Regulates Gene Expression

Abstract

Single particle electron cryo-microscopy (cryo-EM) of RNA alone has not been studied at high resolution as in the case of RNA-protein complexes, because of the intrinsic conformational variability that presents great challenges in particle classification for high resolution structure determination. T-box riboswitches interact with specific tRNAs and sense the corresponding amino acid levels in Gram-positive bacteria. The complete structure of the T-box/tRNA (80 kDa) complex remains unknown. We here report a subnanometer cryo-EM map of this RNA complex, in which major and minor grooves are unambiguously resolved. This result differs from the two small angle X-ray scattering (SAXS) models reported recently, and illustrates the interaction interface between tRNA and T-box riboswitch.

Mass Spectrometry Genotyping of Human Papillomavirus Based on High-Efficiency Selective Enrichment of Nanoparticles

“…Our results show that spermine (SP)-modified NDs have a higher ability to enrich oligonucleotides than PL-coated NDs. Spermine (SP) is frequently used as a stabilization helical structure, particularly in viruses. − In the previous literatures, ,− SP is rarely used to extract and enrich oligonucleotides. Here, we developed a novel SP-NDs-based method to selectively enrich and extract oligonucleotides for MALDI-TOF MS RFMP analysis of the HPV virus.…”