Nucleic Acids Research Advance Access published online on February 7, 2008
Nucleic Acids Research, doi:10.1093/nar/gkn034
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Structural Biology |
Structure/function analysis of yeast ribosomal protein L2
Department of Cell Biology and Molecular Genetics, Microbiology Building Rm. 2135, University of Maryland, College Park, MD, 20742, USA
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Received December 7, 2007. Revised January 18, 2008. Accepted January 21, 2008.
Ribosomal protein L2 is a core element of the large subunit that is highly conserved among all three kingdoms. L2 contacts almost every domain of the large subunit rRNA and participates in an intersubunit bridge with the small subunit rRNA. It contains a solvent-accessible globular domain that interfaces with the solvent accessible side of the large subunit that is linked through a bridge to an extension domain that approaches the peptidyltransferase center. Here, screening of randomly generated library of yeast RPL2A alleles identified three translationally defective mutants, which could be grouped into two classes. The V48D and L125Q mutants map to the globular domain. They strongly affect ribosomal A-site associated functions, peptidyltransferase activity and subunit joining. H215Y, located at the tip of the extended domain interacts with Helix 93. This mutant specifically affects peptidyl–tRNA binding and peptidyltransferase activity. Both classes affect rRNA structure far away from the protein in the A-site of the peptidyltransferase center. These findings suggest that defective interactions with Helix 55 and with the Helix 65–66 structure may indicate a certain degree of flexibility in L2 in the neck region between the two other domains, and that this might help to coordinate tRNA–ribosome interactions.
Present address: Johnathan R. Russ, The University of Chicago Press, Journals Division, 1427 East 60th Street, Chicago, IL 60637, USA The authors wish it to be known that, in their opinion, the first two authors should be regarded as joint First Authors.