Project description:The initiation of translation begins with formation of a ribosome-mRNA complex. In bacteria, the 30S ribosomal subunit is recruited to many mRNAs through both base pairing with the Shine Dalgarno (SD) sequence and RNA-binding by ribosomal protein bS1. Translation can initiate on mRNAs that are being transcribed, and RNA polymerase (RNAP) can promote recruitment of the pioneering 30S. Here we have examined ribosome recruitment to mRNAs using cryogenic electron microscopy (cryo-EM), single-molecule fluorescence co-localization, and whole-cell cross-linking mass spectrometry. Structures of 30S-mRNA complexes show that bS1 delivers the mRNA to the ribosome for SD duplex formation and initial 30S subunit activation. RNAP associates flexibly with the 30S platform during nascent mRNA delivery and accelerates their association in a bS1-dependent manner in vitro. Collectively, our data provide a mechanistic framework for how the SD duplex, ribosomal proteins and RNAP cooperate in 30S recruitment to mRNAs and thereby establish transcription-translation coupling.
Project description:Purpose: The goal of this study is to compare endothelial small RNA transcriptome to identify the target of OASL under basal or stimulated conditions by utilizing miRNA-seq. Methods: Endothelial miRNA profilies of siCTL or siOASL transfected HUVECs were generated by illumina sequencing method, in duplicate. After sequencing, the raw sequence reads are filtered based on quality. The adapter sequences are also trimmed off the raw sequence reads. rRNA removed reads are sequentially aligned to reference genome (GRCh38) and miRNA prediction is performed by miRDeep2. Results: We identified known miRNA in species (miRDeep2) in the HUVECs transfected with siCTL or siOASL. The expression profile of mature miRNA is used to analyze differentially expressed miRNA(DE miRNA). Conclusions: Our study represents the first analysis of endothelial miRNA profiles affected by OASL knockdown with biologic replicates.
Project description:A cDNA library was constructed by Novogene (CA, USA) using a Small RNA Sample Pre Kit, and Illumina sequencing was conducted according to company workflow, using 20 million reads. Raw data were filtered for quality as determined by reads with a quality score > 5, reads containing N < 10%, no 5' primer contaminants, and reads with a 3' primer and insert tag. The 3' primer sequence was trimmed and reads with a poly A/T/G/C were removed