Yeast ribosomal proteins L11 and S18 form a dynamic intersubunit interaction called the B1b/c bridge. Recent high resolution images of the ribosome have enabled targeting of specific residues in this bridge to address how distantly separated regions within the large and small subunits of the ribosome communicate with each other. Mutations were generated in the L11 side of the B1b/c bridge with ...

.............................................................. 2 Chapter 1: A Golden Age of Ribosome Structural Biology ....................................................... 5 1.1 The ribosome is central to all living organisms ................... 5 1.2 30S particles can assemble independently ....................... 9 1.3 30S central domain an interesting target for detailed structural inves...

Assembly of 30S ribosomal subunits from their protein and RNA components requires extensive refolding of the 16S rRNA and is assisted by 10-20 assembly factors in bacteria. We probed the structures of 30S assembly intermediates in E. coli cells, using a synchrotron X-ray beam to generate hydroxyl radical in the cytoplasm. Widespread differences between mature and pre-30S complexes in the absenc...

Human mitochondrial ribosomal protein MRPS18-2 (S18-2) is encoded by a cellular gene that is located on the human chromosome 6p21.3. We discovered that overexpression of the S18-2 protein led to immortalization and de-differentiation of primary rat embryonic fibroblasts. Cells showed anchorage-independent growth pattern. Moreover, pathways characteristic for rapidly proliferating cells were upr...

The majority of constitutive proteins in the bacterial 30S ribosomal subunit have orthologues in Eukarya and Archaea. The eukaryotic counterparts for the remainder (S6, S16, S18 and S20) have not been identified. We assumed that amino acid residues in the ribosomal proteins that contact rRNA are to be constrained in evolution and that the most highly conserved of them are those residues that ar...

The epithelial sodium channel (ENaC) is responsible for Na(+) and fluid absorption across colon, kidney, and airway epithelia. Short palate lung and nasal epithelial clone 1 (SPLUNC1) is a secreted, innate defense protein and an autocrine inhibitor of ENaC that is highly expressed in airway epithelia. While SPLUNC1 has a bactericidal permeability-increasing protein (BPI)-type structure, its NH2...

The crystal structure of a 70-kilodalton ribonucleoprotein complex from the central domain of the Thermus thermophilus 30S ribosomal subunit was solved at 2.6 angstrom resolution. The complex consists of a 104-nucleotide RNA fragment composed of two three-helix junctions that lie at the end of a central helix, and the ribosomal proteins S15, S6, and S18. S15 binds the ribosomal RNA early in the...

Metastatic cancer cells are able to survive the loss of attachment to the extracellular matrix (ECM) by developing resistance to anoikis, a specialized form of apoptosis. Here we investigated resistance to anoikis in nasopharyngeal carcinoma cells (NPC). When detached in culture, the highly metastatic S18 NPC cell line exhibited strong resistance to anoikis, as compared to the poorly metastatic...