3I8H: Elongation Complex of the 70s Ribosome With Three tRnas and Entry 3i8f Contains 50s Ribosomal Subunit

Citation:
Abstract
One key question in protein biosynthesis is how the ribosome couples mRNA and tRNA movements to prevent disruption of weak codon-anticodon interactions and loss of the translational reading frame during translocation. Here we report the complete path of mRNA on the 70S ribosome at the atomic level (3.1-A resolution), and we show that one of the conformational rearrangements that occurs upon transition from initiation to elongation is a narrowing of the downstream mRNA tunnel. This rearrangement triggers formation of a network of interactions between the mRNA downstream of the A-site codon and the elongating ribosome. Our data elucidate the mechanism by which hypermodified nucleoside 2-methylthio-N6 isopentenyl adenosine at position 37 (ms(2)i(6)A37) in tRNA(Phe)(GAA) stabilizes mRNA-tRNA interactions in all three tRNA binding sites. Another network of contacts is formed between this tRNA modification and ribosomal elements surrounding the mRNA E/P kink, resulting in the anchoring of P-site tRNA. These data allow rationalization of how modification deficiencies of ms(2)i(6)A37 in tRNAs may lead to shifts of the translational reading frame.
MMDB ID: 99489
PDB Deposition Date: 2009/7/9
Updated in MMDB: 2012/08 
Experimental Method:
x-ray diffraction
Resolution: 3.1  Å
Source Organism:
Thermus thermophilus HB8
Similar Structures:
Merged PDB IDs:3I8F 3I8G 3I8H 3I8I
Asymmetric Unit for 3I8H: 114-meric
Molecular Components in 3I8H
Label Count Molecule
Proteins (100 molecules)
2
50S Ribosomal Protein L2
Molecule annotation
2
50S Ribosomal Protein L3
Molecule annotation
2
50S Ribosomal Protein L4
Molecule annotation
2
50S Ribosomal Protein L5
Molecule annotation
2
50S Ribosomal Protein L6
Molecule annotation
2
50S Ribosomal Protein L9
Molecule annotation
2
50S Ribosomal Protein L13
Molecule annotation
2
50S Ribosomal Protein L14
Molecule annotation
2
50S Ribosomal Protein L15
Molecule annotation
2
50S Ribosomal Protein L16
Molecule annotation
2
50S Ribosomal Protein L17
Molecule annotation
2
50S Ribosomal Protein L18
Molecule annotation
2
50S Ribosomal Protein L19
Molecule annotation
2
50S Ribosomal Protein L20
Molecule annotation
2
50S Ribosomal Protein L21
Molecule annotation
2
50S Ribosomal Protein L22
Molecule annotation
2
50S Ribosomal Protein L23
Molecule annotation
2
50S Ribosomal Protein L24
Molecule annotation
2
50S Ribosomal Protein L25
Molecule annotation
2
50S Ribosomal Protein L27
Molecule annotation
2
50S Ribosomal Protein L28
Molecule annotation
2
50S Ribosomal Protein L29
Molecule annotation
2
50S Ribosomal Protein L30
Molecule annotation
2
50S Ribosomal Protein L31
Molecule annotation
2
50S Ribosomal Protein L32
Molecule annotation
2
50S Ribosomal Protein L33
Molecule annotation
2
50S Ribosomal Protein L34
Molecule annotation
2
50S Ribosomal Protein L35
Molecule annotation
2
30S Ribosomal Protein S2
Molecule annotation
2
30S Ribosomal Protein S3
Molecule annotation
2
30S Ribosomal Protein S4
Molecule annotation
2
30S Ribosomal Protein S5
Molecule annotation
2
30S Ribosomal Protein S6
Molecule annotation
2
30S Ribosomal Protein S7
Molecule annotation
2
30S Ribosomal Protein S8
Molecule annotation
2
30S Ribosomal Protein S9
Molecule annotation
2
30S Ribosomal Protein S10
Molecule annotation
2
30S Ribosomal Protein S11
Molecule annotation
2
30S Ribosomal Protein S12
Molecule annotation
2
30S Ribosomal Protein S13
Molecule annotation
2
30S Ribosomal Protein S14 Type Z
Molecule annotation
2
30S Ribosomal Protein S15
Molecule annotation
2
30S Ribosomal Protein S16
Molecule annotation
2
30S Ribosomal Protein S17
Molecule annotation
2
30S Ribosomal Protein S18
Molecule annotation
2
30S Ribosomal Protein S19
Molecule annotation
2
30S Ribosomal Protein S20
Molecule annotation
2
30S Ribosomal Protein THX
Molecule annotation
2
23S rRNA
Molecule annotation
1
5S rRNA
Molecule annotation
1
50S Ribosomal Protein L7/l12
Molecule annotation
Nucleotides(6 molecules)
1
23S Ribosomal RNA
Molecule annotation
2
5S Ribosomal RNA
Molecule annotation
2
16S Ribosomal RNA
Molecule annotation
6
tRNA-phe With Unmodified Nucleotides Except for Mia37
Molecule annotation
2
mRNA
Molecule annotation
1
16S Ribosomal RNA
Molecule annotation
Chemicals (5351 molecules)
1
5345
Molecule information is not avaliable.
2
6
Molecule information is not avaliable.
* Click molecule labels to explore molecular sequence information.

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