HyPhy, acronym for Hypothesis Testing Using Phylogenies (www.hyphy.org) was written & designed by Kosakovsky Pond and workers to provide likelihood-based analyses on molecular evolutionary data sets and help detect differential rates of variability within a coding sequence datasets. It is freely available, has a Graphical User Interface and can be used by anyone with or without much computer language or programming exposure.
It was earlier presumed that substitution rates were uniform over an alignment of homologous DNA/Protein sequences but many workers studying molecular evolutionary processes influencing rates and patterns of evolution negated this presumption with quite a lot of data and this is especially true for highly evolving gene family datasets and for viral genomes. Natural selection takes place at different domains/regions/sites which are under positive, negative or neutral selection pressures. Positive selection originates with more of non-synonymous substitutions in a protein coding sequence influencing the fitness advantage (protein structure and function) of an organism whereas negative selection takes place with more of synonymous substitution in a protein coding sequence leaving the amino acid sequence or protein structure and function unchanged. A neutral evolution is said to be taking place when the non-synonymous substitutions do not affect the protein structure and function and rate of non-synonymous substitutions. The rate of synonymous and non-synonymous substitutions is given by dS and dN respectively. In the case of neutral evolution, dS and dN are observed to be in equilibrium. Accordingly, the ratio of dN/dS given by ω=β/α (also referred to as dN/dS) has become a standard measure of selective pressure. The total ω for a sequence alignment is referred to as Global ω. Global ω with a value of approximately 1 signifies neutral evolution, below 1 suggests negative selection whereas ω more than 1 implies positive selection. To start with the analyses, all one needs is, a suitable codon substitution model as detected by MODELTEST program (available online), a nexus formatted sequence alignment file (must be codon data file) and a Maximum Likelihood tree of the data.
Datamonkey is a web interface (http://www.datamonkey.org) which uses HyPhy batch files to execute most of its tools and packages for the computational analyses. This web interface can be used for estimating dS and dN over an alignment of coding sequences and also for identifying codons and lineages under selection. It also provides “state of the art” tests of codon based models to infer signatures of positive Darwinian selection by comparing rates of synonymous (dS) versus non-synonymous (dN) mutations even in the presence of recombination. It actually reports ω (=dN/dS) using a variety of evolutionary models. Apart from this, Datamonkey also offers a number of packages such as GARD, SLAC, REL, FEL, EVOBLAST etc. These will be discussed in the next issue. Keep reading!!
A comprehensive list of references on the article are available upon request to the author ([email protected])
[Tutorial] Installing VIAMD on Ubuntu (Linux).
Visual Interactive Analysis of Molecular Dynamics (VIAMD) is a tool that allows the interactive analysis of molecular dynamics simulations . In this article, we are installing it on Ubuntu (Linux).
[Tutorial] Performing docking using DockingPie plugin in PyMOL.
How to install the DockingPie plugin on PyMOL?
DockingPie  is a plugin of PyMOL  made to fulfill the purpose of docking within the PyMOL interface. This plugin will allow you to dock using four different algorithms, namely, Vina, RxDock, SMINA, and ADFR. It will also allow you to perform flexible docking. Though the installation procedure is the same for all OSs, in this article, we are installing this plugin on Ubuntu (Linux).
How to predict binding pocket/site using CASTp server?
Video Tutorial: Calculating binding pocket volume using PyVol plugin.
How to generate topology from SMILES for MD Simulation?
[Tutorial] Installing jdock on Ubuntu (Linux).
jdock is an extended version of idock . It has the same features as the idock along with some bug fixes. However, the binary name and the GitHub repository names are changed. We are installing jdock on Ubuntu (Linux).
How to install GMXPBSA on Ubuntu (Linux)?
[Tutorial] Installing Pyrx on Windows.
How to solve ‘Could NOT find CUDA: Found unsuitable version “10.1”‘ error during GROMACS installation?
Compiling GROMACS  with GPU can be trivial. Previously, we have provided a few articles on the same. In this article, we will solve an error frequently occurring during GROMACS installation.
Installing Autodock4 on MacOS.
How to install Autodock4 on Ubuntu?
DS Visualizer: Uses & Applications
Protein structure & folding information exploited from remote homologs.
Remote homologs are similar protein structures that share similar functions, but there is no easily detectable sequence similarity in them. A new study has revealed that the protein folding information can be exploited from remote homologous structures. A new tool is developed to recognize such proteins and predict their structure and folding pathway. (more…)
Pathonoia- A new tool to detect pathogens in RNA-seq data.
Detecting viruses and bacteria in RNA-seq data with less false positive rate is a difficult task. A new tool is introduced to detect pathogens in RNA-seq data with high precision and recall known as Pathonoia .
AlphaFill- New algorithm to fill ligands in AlphaFold models.
AlphaFold is a popular artificial intelligence based protein prediction tool . Though it predicts good protein structures, it lacks the capability to predict the small molecules present in the structure such as ligands. For this purpose, AlphaFill is introduced by Hekkelman et al.,. (more…)