Thus if the cell needs to respond quickly, such as in a disease or another emergency, it may only need to produce few parts to switch on or tune the machine. On the other hand, if something shouldn't happen, it may only need to block the production of a few molecules.
Patrick Aloy and Rob Russell at EMBL used sophisticated computer techniques to reveal the modular organisation of these cellular machines. "This is the most complete set of protein complexes available and probably the set with the highest quality," Aloy says. "Most proteomics studies in the past have shown whether molecules interact or not, in a 'yes/no' way. The completeness of this data lets us see how likely any particular molecule is to bind to another. By combining such measurements for all the proteins in the cell, we discovered new complexes and revealed their modular nature."
"Investigating protein complexes has always posed a tricky problem ?they're too small to be studied by microscopes, and generally too large to be studied by techniques like X-ray crystallography," says Russell. "But they play such a crucial role in the cell that we need to fill in this gap. There's still a huge amount to be learned from this data and from the methods we are developing to combine computational and biochemical investigations of the cell."
"This is an important milestone towards a more global and systems-wide understanding of the cells of organisms ranging from yeast to humans," says Peer Bork, Head of the Structural and Computational Biology Unit at EMBL, and one of the authors of the paper. "Ultimately we hope to achieve a 'molecular anatomy' that takes us from the level of the entire cell to the much deeper level of all the molecules and atoms th
Source:European Molecular Biology Laboratory