PDBsum entry 3bns

RNA

PDB id: 3bns

Contents

DNA/RNA

Metals

__K ×2

Waters ×102

PDB id:

3bns

Name:

RNA

Title:

Crystal structure of the homo sapiens mitochondrial ribosomal decoding site (a1555g mutant, br-derivative)

Structure:

A site of human mitochondrial ribosome, chain three. Chain: a, c. Engineered: yes. Mutation: yes. A site of human mitochondrial ribosome, chain two. Chain: b. Engineered: yes. Mutation: yes. A site of human mitochondrial ribosome, chain three.

Source:

Synthetic: yes. Synthetic: yes

Resolution:

1.90Å R-factor: 0.247 R-free: 0.260

Authors:

J.Kondo,E.Westhof

Key ref:

J.Kondo and E.Westhof (2008). The bacterial and mitochondrial ribosomal A-site molecular switches possess different conformational substates. Nucleic Acids Res, 36, 2654-2666. PubMed id: 18346970

Date:

14-Dec-07 Release date: 24-Jun-08

DNA/RNA chains

U-U-G-C-G-U-C-A-C-C-5BU-C-G-A-G-C-A-A-G-U-C-G-C 23 bases

U-G-C-G-U-C-A-C-C-5BU-C-G-A-G-C-A-A-G-U-C-G-C 22 bases

U-U-G-C-G-U-C-A-C-C-5BU-C-G-A-G-C-A-A-G-U-C-G-C 23 bases

G-C-G-U-C-A-C-C-5BU-C-G-A-G-C-A-A-G-U-C-G-C 21 bases

Nucleic Acids Res 36:2654-2666 (2008)

PubMed id: 18346970

The bacterial and mitochondrial ribosomal A-site molecular switches possess different conformational substates.

J.Kondo, E.Westhof.

ABSTRACT

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.