3bns

Publication Abstract from PubMed

The A site of the small ribosomal subunit participates in the fidelity of decoding by switching between two states, a resting 'off' state and an active decoding 'on' state. Eight crystal structures of RNA duplexes containing two minimal decoding A sites of the Homo sapiens mitochondrial wild-type, the A1555G mutant or bacteria have been solved. The resting 'off' state of the mitochondrial wild-type A site is surprisingly different from that of the bacterial A site. The mitochondrial A1555G mutant has two types of the 'off' states; one is similar to the mitochondrial wild-type 'off' state and the other is similar to the bacterial 'off' state. Our present results indicate that the dynamics of the A site in bacteria and mitochondria are different, a property probably related to the small number of tRNAs used for decoding in mitochondria. Based on these structures, we propose a hypothesis for the molecular mechanism of non-syndromic hearing loss due to the mitochondrial A1555G mutation.

The bacterial and mitochondrial ribosomal A-site molecular switches possess different conformational substates.,Kondo J, Westhof E Nucleic Acids Res. 2008 May;36(8):2654-66. Epub 2008 Mar 16. PMID:18346970^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.