A Programmable Dual-RNA–Guided DNA Endonuclease in Adaptive Bacterial Immunity

Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) systems provide bacteria and archaea with adaptive immunity against viruses and plasmids by using CRISPR RNAs (crRNAs) to guide the silencing of invading nucleic acids. We show here that in a subset of these systems, the mature crRNA that is base-paired to trans-activating crRNA (tracrRNA) forms a … Read moreA Programmable Dual-RNA–Guided DNA Endonuclease in Adaptive Bacterial Immunity

Maximum expected accuracy structural neighbors of an RNA secondary structure

Since RNA molecules regulate genes and control alternative splicing by allostery, it is important to develop algorithms to predict RNA conformational switches. Some tools, such as paRNAss, RNAshapes and RNAbor, can be used to predict potential conformational switches; nevertheless, no existent tool can detect general (i.e., not family specific) entire riboswitches (both aptamer and expression platform) with accuracy. Thus, the development of additional algorithms to detect conformational switches seems important, especially since the difference in free energy between the two metastable secondary structures may be as large as 15-20 kcal/mol. It has recently emerged that RNA secondary structure can be more accurately predicted by computing the maximum expected accuracy (MEA) structure, rather than the minimum free energy (MFE) structure.


Source code for RNAborMEA can be downloaded from http://sourceforge.net/projects/rnabormea/ or http://bioinformatics.bc.edu/clotelab/RNAborMEA/

“RISC” of Bacteria and Archaea

Restriction-modification systems, abortive-phage phenotypes, toxin-antitoxins and other innate defense systems, in the past, have been shown in familiar chapters in typical microbiology textbook, while now what if I say in prokaryotes world “RISC” can serve a role for new kind of antiviral defense, in addition the “RNAi” can even be engineered and designed to lead … Read more“RISC” of Bacteria and Archaea

microRNAs quantitative assay with Splinted Ligation

Do you still use Northern Blot to quantitate microRNAs expression? Here I recommend Splinted Ligation Assay[1,2], though this method is an old story (published in 2007).   Detection of miRNAs using splinted ligation. Schematic depiction of the assay process. As described in the text, the assay involves: (1) Labeling of the ligation oligonucleotide; (2) concurrent … Read moremicroRNAs quantitative assay with Splinted Ligation

Computer Program Enrich Understandings to RNA motifs

DNA carries and passes the genetic information with nucleotides sequences, but in some virus RNA does the job instead of DNA.  In addition, the 3D structure of RNA, RNA motif, shows more various roles in cellular functions. It means that only with sequence information we cannot fully understand the RNA roles and functions. Detecting and … Read moreComputer Program Enrich Understandings to RNA motifs