5CH4: Peptide-bound State Of Thermus Thermophilus Secyeg

The bacterial SecYEG translocon functions as a conserved protein-conducting channel. Conformational transitions of SecYEG allow protein translocation across the membrane without perturbation of membrane permeability. Here, we report the crystal structures of intact SecYEG at 2.7-A resolution and of peptide-bound SecYEG at 3.6-A resolution. The higher-resolution structure revealed that the cytoplasmic loop of SecG covers the hourglass-shaped channel, which was confirmed to also occur in the membrane by disulfide bond formation analysis and molecular dynamics simulation. The cytoplasmic loop may be involved in protein translocation. In addition, the previously unknown peptide-bound crystal structure of SecYEG implies that interactions between the cytoplasmic side of SecY and signal peptides are related to lateral gate opening at the first step of protein translocation. These SecYEG structures therefore provide a number of structural insights into the Sec machinery for further study.
PDB ID: 5CH4Download
MMDB ID: 134419
PDB Deposition Date: 2015/7/10
Updated in MMDB: 2015/12
Experimental Method:
x-ray diffraction
Resolution: 3.64  Å
Source Organism:
Similar Structures:
Biological Unit for 5CH4: trimeric; determined by author and by software (PISA)
Molecular Components in 5CH4
Label Count Molecule
Proteins (3 molecules)
Protein Translocase Subunit Secy(Gene symbol: secY)
Molecule annotation
Protein Translocase Subunit Sece(Gene symbol: secE)
Molecule annotation
Putative Preprotein Translocase, Secg Subunit
Molecule annotation
* Click molecule labels to explore molecular sequence information.

Citing MMDB