Three-dimensional structure model and predicted ATP interaction rewiring of a deviant RNA ligase 2

PSnpBind: a database of mutated binding site protein-ligand complexes constructed using a multithreaded virtual screening workflow

A key concept in drug design is how natural variants, especially the ones occurring in the binding site of drug targets, affect the inter-individual drug response and efficacy by altering binding affinity. These effects have been studied on very limited and small datasets while, ideally, a large dataset of binding affinity changes due to binding site single-nucleotide polymorphisms (SNPs) is needed for evaluation. However, to the best of our knowledge, such a dataset does not exist. Thus, a reference dataset of ligands binding affinities to proteins with all their reported binding sites' variants was constructed using a molecular docking approach. Having a large database of protein-ligand complexes covering a wide range of binding pocket mutations and a large small molecules' landscape is of great importance for several types of studies. For example, developing machine learning algorithms to predict protein-ligand affinity or a SNP effect on it requires an extensive amount of data. In this work, we present PSnpBind: A large database of 0.6 million mutated binding site protein-ligand complexes constructed using a multithreaded virtual screening workflow. It provides a web interface to explore and visualize the protein-ligand complexes and a REST API to programmatically access the different aspects of the database contents. PSnpBind is open source and freely available at https://psnpbind.org .

Post-transcriptional mending of gene sequences: Looking under the hood of mitochondrial gene expression in diplonemids

The instructions to make proteins and structural RNAs are laid down in gene sequences. Yet, in certain instances, these primary instructions need to be modified considerably during gene expression, most often at the transcript level. Here we review a case of massive post-transcriptional revisions via trans-splicing and RNA editing, a phenomenon occurring in mitochondria of a recently recognized protist group, the diplonemids. As of now, the various post-transcriptional steps have been cataloged in detail, but how these processes function is still unknown. Since genetic manipulation techniques such as gene replacement and RNA interference have not yet been established for these organisms, alternative strategies have to be deployed. Here, we discuss the experimental and bioinformatics approaches that promise to unravel the molecular machineries of trans-splicing and RNA editing in Diplonema mitochondria.

Genes in Hiding

Unrecognizable genes are an unsettling problem in genomics. Here, we survey the various types of cryptic genes and the corresponding deciphering strategies employed by cells. Encryption that renders genes substantially different from homologs in other species includes sequence substitution, insertion, deletion, fragmentation plus scrambling, and invasion by mobile genetic elements. Cells decode cryptic genes at the DNA, RNA or protein level. We will focus on a recently discovered case of unparalleled encryption involving massive gene fragmentation and nucleotide deletions and substitutions, occurring in the mitochondrial genome of a poorly understood protist group, the diplonemids. This example illustrates that comprehensive gene detection requires not only auxiliary sequence information - transcriptome and proteome data - but also knowledge about a cell's deciphering arsenal.