Conformational independence of N- and C-domains in ribosomal protein L7/L12 and in the complex with protein L10.

Isolated N- (1-37) and C-terminal (47-120) fragments of L7 protein, and pentameric (L7)4L10 complex were studied by NMR spectroscopy in solution. The results indicate that the dimer state of the 1-37 fragment with a helical hairpin conformation is identical to the N-terminal structure of the intact L7 dimer. The C-terminal domain of the L7 protein does not participate in (L7)4L10 complex formation. The overall motions of the L7 C-domains are essentially independent both in the L7 dimer and in the (L7)4L10 complex. Conformational motions on a millisecond time scale are detected in the (L7)4L10 complex. The possible relevance of these motions to the biological function of L7/L12 is discussed.