Hollows, voids, gaps and tunnels in the ribosome

Recent years in prokaryotic ribosome research may be characterized by major conceptual revisions, coupled with attempts at resolving ambiguities (e.g. [1,2,3’,4*]) and the introduction of substantial spatial rearrangements [ 51. Thus, the ribosomal functions can no longer be attributed solely to the ribosomal proteins [6**], and the once favorable research object, the Escbe&biu coli ribosome, is gradually being substituted by more robust ones from thermophilic or halophilic bacteria [ 1,7**,8*]. In addition, compelling evidence has emerged indicating that polyphenylalanine, the product of the universal assay for ribosomal activity, may emerge from the ribosome by a path dictated by its special chemical nature, different from that of natural proteins, thus poorly representing the nascent proteins [9**]. Furthermore, the ribosome, traditionally conceptualized as a compact network, was found to contains a variety of hollows.