HIV viruses budding from surface of human T cell. © NIBSC/Photo Researchers, Inc.
HIV inner shell structure revealed
Researchers have for the first time unravelled the complex structure of the inner protein shell of HIV. The US team, reporting in Nature, also worked out exactly how all the components of the shell or ‘capsid’ fit together at the atomic level.
Until now the exact structure had proved elusive because of the capsid’s large size and irregular shape. The finding opens the way for new types of drugs, the researchers from the University of Pittsburgh said.
It was already known that the capsid, which sits inside the outer membrane of the virus, was a cone-shaped shell made up of protein sub-units in a lattice formation. But because it is huge, asymmetrical and non-uniform, standard techniques for working out the structure had proved ineffective.
The team used advanced imaging techniques and a supercomputer to calculate how the 1,300 proteins which make up the cone-shaped capsid fit together.