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Printable Handouts
Navigable Slide Index
- Introduction
- Schematic structure of the ribosome (1964)
- Text book ribosome structure
- Structure of the ribosome with tRNA and mRNA
- Venki Ramakrishnan
- Model of the large ribosomal subunit
- Nenad Ban
- Poul Nissen
- Structure of the ribosomal large subunit
- How porous is the interior of the the ribosome?
- The interior of the large subunit
- Slices through the ribosome
- Escape radius of the tunnel
- Branches in the exit tunnel
- A view of the tunnel at different radii
- Map of the exit tunnel
- Inside the tunnel
- Tunnel visions
- Source of ribosome's catalytic power
- Sources of enzyme catalytic power
- Structures of states in a process are important
- Many snapshots are required for understanding
- Peptydil transferase reaction (1)
- Jeff Hansen
- Analogue of the transition state
- Binding of Yarus transition state analogue
- Active site is composed of tightly packed RNA
- The substrate binding region is highly conserved
- Proximity of proteins to the active site
- No proteins found within 18A from active site
- The ribosome is a ribozyme
- Martin Schmeing
- Activity of large subunit crystals
- Peptydil transferase reaction (2)
- Results of peptydil transferase assay
- Peptid-bond formation site
- Peptid-bond formation site with substrate analogue
- Prevention of peptydil tRNA hydrolysis
- Induced fit
- Stimulation of P-site fMet-tRNA deacylation
- Occluding water molecules from attack positions
- ChPmn-CCApcb-peptidyl transferase structure
- CChPmn-CCApcb-peptidyl transferase structure
- DCA-peptidyl transferase structure
- Conformational changes induced by substrate (1)
- Conformational changes induced by substrate (2)
- The pre-reaction ground state
- Effect of mutations in A2486
- Effect of 2-OH removal from A76 of the P-site
- Possible role for 2-OH on A76 of the P-site
- Possible activation of 2-OH of A76 by a metal ion
- Interaction of 2-OH of A76 with solvent molecule
- No magnesium ions are coordinated to A76 2-OH
- Metal ion not bound to the 2'OH of the P-site A76
- Stabilization of tetrahedral carbon transition state
- Transition state oxyanion points away from A2486
- The oxyanion hole is a water molecule
- Contributors to the ribosome's catalytic power
- E-site proteins of eubacteria and archaea
- Location of E-site relative to A and P-sites
- RNA in the E-site
- Conformation of CCA in the E-site
- Protein component of the E-site is not conserved
- CCA binding to T.th. 70S versus H.ma. 50S
- CCA and 13-deoxytedanolide binding to H.ma. 50S
- Summary of CCA/13-deoxytedanolide binding
- The peptidyl transferase reaction (3)
- Acknowledgements
Topics Covered
- Overview of protein synthesis by the ribosome
- Nature of the polypeptide exit tunnel in the large subunit
- The ribosome is a ribozyme
- Substrate induced fit at the peptidyl transferase center
- Proton shuttle mechanism and transition state stabilization
- Substrate interactions at the large subunit E-site
- Movie of the peptidyl transferase reaction
Talk Citation
Steitz, T. (2008, May 15). The structural basis for how the large ribosomal subunit catalyses peptide bond formation [Video file]. In The Biomedical & Life Sciences Collection, Henry Stewart Talks. Retrieved August 31, 2024, from https://doi.org/10.69645/XPYR2559.Export Citation (RIS)
Publication History
Financial Disclosures
- Prof. Thomas Steitz has not informed HSTalks of any commercial/financial relationship that it is appropriate to disclose.
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