Identifying functionally important proteins that are essential to the survival of a bacterial cell is of considerable interest in the development of new antimicrobial agents. In this study, we analyse the protein interaction network of the gram-positive bacteria Bacillus subtilis using data from the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) database. Protein interaction networks were represented as graphs of interacting nodes and edges in which the nodes represent proteins and the edges represent interactions between proteins. We used different computational techniques to analyse the topological structures of the network and to derive a list of the structurally important proteins within the network based on the relative damaging potential of each individual protein. We then ranked proteins in the order of structural importance within the network.
Among 801 proteins involving 5017 interactions, 54% of proteins in the top 1% ranking selected by our method were encoded by functionally essential genes of Bacillus subtilis. Furthermore, a total of 38 structurally essential proteins were found to be encoded by functionally essential genes among the top 10% ranking, which account for 50% of the total number of essential proteins present in the protein interaction data analysed. These results show that the structural arrangement of proteins may provide vital clues about the functionality of proteins. The methods developed in this study could be used to rank proteins to determine their potential significance for drug target experiments.
Olusola received his PhD degree in Mathematics from University of Newcastle in 2000. In his doctorate degree research he developed analytical and numerical methods for studying the flow of liquids at absolute zero temperatures.
Immediately after his doctoral degree research, he worked as a research fellow at Stanford University, California and NASA Ames Research Centre, California developing mathematical models for motion of gas cloud in Protoplanetary Nebula.
Olusola is currently working on the eXSys project (e-Science Solutions for the Analysis of Complex Systems).