However, recent advances in technology have allowed scientists to look closer at virus structures. Upgrades to the virus facilities at the Diamond synchrotron have opened up new ways of perceiving the microscopic world, and made it possible to scrutinise viruses in minute detail. The Oxford group have found that identifying the structure of viruses responsible for diseases such as HIV, Hepatitis and the common cold can help them to trace each virus’s evolutionary history. The scientists used Diamond’s macromolecular crystallography technology to investigate a large group, or ‘superlineage’, of viruses that inhabit extreme habitats. Using Diamond’s I03 beamline, scientists can study whole viruses under intense synchrotron light. The Oxford team used I03 to study a type of virus known as bacteriophage P23-77, which infects bacteria. This virus is found in New Zealand’s alkaline hot springs, where it flourishes at temperatures of 65-75°C, an environment that would quickly destroy most other life.
The team, which included Diamond’s Jonathan Grimes and Dave Stuart, found that the hot springs virus has a distinct structure, unlike that of other viruses. Prof. Stuart, Life Sciences Director at Diamond and MRC Professor of Structural Biology at the University of Oxford, commented on the significance of the boiling water where the virus was found; “Remarkably extreme places on earth are home to some tiny living fossils - viruses whose bacterial hosts have changed little over may millions of years. The structure is beautifully preserved, allowing us to see how viruses probably looked several billions of years ago.”
The shell is shaped like an icosahedron, and is made up of a number of triangular-shaped sides. It also has turrets that project from the shell, giving the virus the appearance of having protective towers. These unique features have led the scientist to conclude that the hot springs virus is part of an entirely new lineage. Bacteriophage P23-77’s crenellated shell suggests that it is far more ancient than other viruses; perhaps one of the oldest in existence. The sheer heat of the New Zealand springs seems to have preserved the virus and halted its evolution, so that it has remained virtually the same over billions of years.
Diamond Fellow and University Research Lecturer in Structural Biology at the University of Oxford, Dr. Grimes, noted the remarkable condition of the ancient virus; “These viruses seem to have changed little since before cellular life separated into bacteria and other organisms. Their structures are more complex than viruses that have adapted in higher cellular life forms; this highlights the fact that evolution is not a simple linear process, but is in fact highly complex”.
The discovery of this vestige of a primordial lineage of pathogens reveals a fundamental insight into the ancient origins of viruses and the way that they have evolved over time. Future scientific studies of the hot springs virus should also reveal more about the earliest natural era, before many other forms of life existed. Already, this ancestral virus provides a fascinating window into the natural history of our world.