Bioinformatics is a discipline at the intersection of biology, computer science, information technology and mathematics. It aims at integrating and analysing a wealth of biological data with the aim of identifying and assigning a function to each of the parts list of a living organism and understanding the incredibly complex processes that define life at a systems level. It is applied, for example, in the construction of genetic and physical maps of genomes, gene discovery, the inference of the molecular function and three-dimensional structure of their products, the interpretation of the effect of gene variations on the phenotype, the reconstruction of interaction and signal transduction pathways and the simulation of biological systems. Bioinformatics is an essential part of modern biology and a key player in the quest for a complete systems-level understanding of a living cell and of an organism.

Key concepts

• Biological data are being produced at an unprecedented speed and need to be organized and integrated.
  
• Bioinformatics, or computational biology, is the discipline that uses computational tools for analysing biological data and adds ‘biological’ value to them.
  
• The complete DNA sequences of many genomes, including Homo sapiens, have been elucidated and need to be annotated, that is, associated to their biological function.
  
• Proteins, the products of genes, perform most of the functions of life.
  
• The function of a protein can be deduced by its evolutionary history or by analysing the three-dimensional shape that it assumes.
  
• The evolutionary history of a protein (a gene) can be deduced by comparing its sequence with those of all other known proteins (or genes).
  
• The number of possible three-dimensional structures of a protein is almost infinite and the correct one cannot be selected, as of today, on the basis of first principles.
  
• Empirical methods, based on evolution or on the body of experimental knowledge on protein structures, can be used to infer the unknown structure of a protein.
  
• The future challenge of bioinformatics is to use and combine available data on sequences, three-dimensional structures, interactions, abundance and temporal patterns of expression to obtain a systems level understanding of life.