Biological function made crystal clear - annotation of hypothetical proteins via structural genomics.

Many of the gene products of completely sequenced organisms are 'hypothetical' - they cannot be related to any previously characterized proteins - and so are of completely unknown function. Structural studies provide one means of obtaining functional information in these cases. A 'structural genomics' project has been initiated aimed at determining the structures of 50 hypothetical proteins from Haemophilus influenzae to gain an understanding of their function. Each stage of the project - target selection, protein production, crystallization, structure determination, and structure analysis - makes use of recent advances to streamline procedures. Early results from this and similar projects are encouraging in that some level of functional understanding can be deduced from experimentally solved structures.