Escherichia coli LepA, the ribosomal back translocase
From Proteopedia
The Crystal Structure of LepA, the ribosomal back translocase
Publication Abstract from PubMed
LepA is a highly conserved elongation factor that promotes the back translocation of tRNAs on the ribosome during the elongation cycle. We have determined the crystal structure of LepA from Escherichia coli at 2.8-A resolution. The high degree of sequence identity between LepA and EF-G is reflected in the structural similarity between the individual homologous domains of LepA and EF-G. However, the orientation of domains III and V in LepA differs from their orientations in EF-G. LepA also contains a C-terminal domain (CTD) not found in EF-G that has a previously unobserved protein fold. The high structural similarity between LepA and EF-G enabled us to derive a homology model for LepA bound to the ribosome using a 7.3-A cryo-EM structure of a complex between EF-G and the 70S ribosome. In this model, the very electrostatically positive CTD of LepA is placed in the direct vicinity of the A site of the large ribosomal subunit, suggesting a possible interaction between the CTD and the back translocated tRNA or 23S rRNA. The structure of LepA, the ribosomal back translocase., Evans RN, Blaha G, Bailey S, Steitz TA, Proc Natl Acad Sci U S A. 2008 Mar 25;105(12):4673-8. Epub 2008 Mar 24. PMID:18362332 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. About this StructureThe BasicsThe crystallographic asymmetric unit of the solved structure (3cb4) contains 6 monomers of LepA. The LepA monomer. LepA and EF-G Are SimilarThe high degree of sequence similarity between LepA and EF-G is reflected in the structural similarity between the individual homologous domains of LepA and EF-G. The domains are colored according to figure 1 of the paper describing the structure.
Color LepA and Ef-G differently.
Overall superposition of LepA and EF-G. Note that the individual domains of LepA and EF-G, such as III V, superimpose much better when done separately (shown in figure 2 of the paper describing the structure). PDB Entry3cb4 is a 6 chains structure of sequences from Escherichia coli k12. Full crystallographic information is available from OCA. Fancy, high-quality cartoons on/off Related Structures and Topics
3D structures of LepAUpdated on 28-December-2017 3cbd – EcLepA – Escherichia coli 2ywe – AaLepA – Aquifex aeolicus Reference
Page begun with original page seeded for PDB entry 3cb4 by OCA on Wed Jun 3 08:45:42 2009 |
| |||||||||||
Proteopedia Page Contributors and Editors (what is this?)
Wayne Decatur, Michal Harel, Alexander Berchansky, Joel L. Sussman, David Canner
Categories: Escherichia coli k12 | Bailey, S. | Blaha, G. | Evans, R N. | Steitz, T A. | Gtp-binding | Gtpase | Membrane | Nucleotide-binding | Ob-fold | Periplasm | Translation | Topic Page
