2017  0,977
2016  0,799
2015  0,662
2014  0,740
2013  0,739
2012  0,637
2011  0,658
2010  0,654
2009  0,570
2008  0,849
2007  0,805
2006  0,330
2005  0,435
2004  0,623
2003  0,567
2002  0,641
2001  0,490
2000  0,477
1999  0,762
1998  0,785
1997  0,507
1996  0,518
1995  0,502
Vol 45(2011) N 6 p. 959-966;
A.V. Ivanov, A.A. Malygin, G.G. Karpova*

Binding of the Human Ribosomal Protein S13 to the Central Domain of 18S rRNA

Institute of Chemical biology and Fundamental Medicine of Siberian Branch of Russian Academy of Sciences, Novosibirsk, 630090

Received - 2011-03-11; Accepted - 2011-03-24

Human ribosomal protein S13 is a structural element of the small ribosome subunit. It is homologous to the eubacterial ribosomal protein S15 and additionally possesses an extended N-terminal region, characteristic of the S15p family in eukaryotes and archaea. In the present study, we investigated the binding of the recombinant ribosomal protein S13 and its mutant forms containing deletions or amino acid substitutions in different regions to an RNA transcript representing a fragment of the central domain of the 18S rRNA. It was shown that substitution of ultra-conservative residues H101 and D108, as well as deletions of either 29 C-terminal or 27 N-terminal residues, substantially reduced the protein affinity to the RNA transcript. Deletion of 54 C-terminal or 80 N-terminal residues rendered the protein fully incapable of RNA binding. Using a footprinting assay, we identified those sites in the RNA transcript that change their accessibility to hydroxyl radicals as a result of binding either full-length protein S13 or its mutant lacking 27 N-terminal residues. It was shown that these sites are located mainly in the H22 helix of the 18S rRNA and near its junction with the H20 helix and that they largely correspond to rRNA contacts with the conserved part of the protein. Thus, the binding of the ribosomal protein S13 to the 18S rRNA is provided mainly by conserved motifs of the protein corresponding to those motifs in its eubacterial homologue that are involved in the interaction with the 16S rRNA in the 30S subunit. The role of the N-terminal region of S13 in its binding to the central domain of the 18S rRNA is discussed.

human ribosomal protein S13, 18S rRNA, footprinting, structure of the 40S ribosome subunit, RNA-protein interactions