[Extraribosomal functions of bacterial ribosomal proteins]

Though their primary role in a cell is to serve as integral components of protein synthesis machinery, the ribosome, many of them have functions beyond the ribosome (the phenomenon known as moonlighting), acting either as individual regulatory proteins or in complexes with other cellular components. Extraribosomal activities of some ribosomal proteins have been observed as early as in the 1970-1980s. During the last years both a list of r-proteins-moonlighters and the repertoire of their additional functions beyond the ribosome have been greatly expanded, mainly due to newly developed techniques for dissecting RNA/DNA-protein or protein-protein interactions within functional complexes involved in various cellular processes. In this review, we surveyed information on the experimentally proven as well as on presumptive extraribosomal functions which may be performed by bacterial r-proteins in a cell.