The identification of transient or readily reversible interactions between proteins is a difficult problem that has been addressed with various methods. Ruotolo et al. have now applied mass spectrometry to the problem to exploit its advantages of sensitivity and speed. They show that the trp RNA binding attenuation protein (TRAP) maintains its 11-membered ringlike structure in the gas phase and that binding of RNA and tryptophan influences the shape and stability of the ring in a fashion consistent with its known behavior in aqueous solution.
B. T. Ruotolo, K. Giles, I. Campuzano, A. M. Sandercock, R. H. Bateman, C. V. Robinson, Evidence for macromolecular protein rings in the absence of bulk water. Science 310, 1658-1661 (2005). [Abstract] [Full Text]
