Molecular phylogenetics of Black Cobra (Naja naja) in Pakistan

Background: Snakes are found on every continent in the world except Antarctica, and on smaller land masses. Being ecologically important, they also cause a large number of bites, leading to millions of deaths. Mitochondrial and nuclear gene sequences are being used to identify, characterize, and infer genetic biodiversity among different snake species. Furthermore, phylogenetics helps in inferring the relationships and evolutionary histories among these species. Black cobra is one of the four most venomous snakes in Pakistan. Four mitochondrial (ND4, Cytochrome b, 12S rRNA, and 16S rRNA) and four nuclear (C-mos, RAG-1, BDNF, and NT3) genes were used to trace diversity and infer the phylogenetic relationship of black cobra in Pakistan. Results: Almost similar phylogenies were obtained through maximum likelihood and Bayesian inference, showing two species of cobra in Pakistan, namely, black cobra (Naja naja) and brown cobra (Naja oxiana). All Naja species were divided into three clades: black cobra (N. naja) and brown cobra (N. oxiana) cladding with different species of Naja; N. naja (Pakistan) cladding with N. naja from Nepal; and N. oxiana showed close relationship with Naja kaouthia from Thailand and Naja siamensis from Thailand. Conclusion: It was confirmed genetically that there are two cobra species in Pakistan, i.e., black and brown cobras. This study will help in not only genetic conservation but also developing anti-venom against snake species.

The accuracy of protein structure alignment servers

Background: Protein structural alignment is one of the most fundamental and crucial areas of research in the domain of computational structural biology. Comparison of a protein structure with known structures helps to classify it as a new or belonging to a known group of proteins. This, in turn, is useful to determine the function of protein, its evolutionary relationship with other protein molecules and grasping principles underlying protein architecture and folding. Results: A large number of protein structure alignment methods are available. Each protein structure alignment tool has its own strengths and weaknesses that need to be highlighted. We compared and presented results ofsix most popular and publically available servers for protein structure comparison. These web-based servers were compared with the respect to functionality (features provided by these servers) and accuracy (how well the structural comparison is performed). The CATH was used as a reference. The results showed that overall CE was top performer. DALI and PhyreStorm showed similar results whereas PDBeFold showed the lowest performance. In case of few secondary structural elements, CE, DALI and PhyreStorm gave 100% success rate. Conclusion: Overall none of the structural alignment servers showed 100% success rate. Studies of overall performance, effect of mainly alpha and effect of mainly beta showed consistent performance. CE, DALI, FatCat and PhyreStorm showed more than 90% success rate.