4L9O: Crystal Structure of the Sec13-Sec16 blade-inserted complex from Pichia pastoris

During the budding of coat protein complex II (COPII) vesicles from transitional endoplasmic reticulum (tER) sites, Sec16 has been proposed to play two distinct roles: negatively regulating COPII turnover and organizing COPII assembly at tER sites. We tested these ideas using the yeast Pichia pastoris. Redistribution of Sec16 to the cytosol accelerates tER dynamics, supporting a negative regulatory role for Sec16. To evaluate a possible COPII organization role, we dissected the functional regions of Sec16. The central conserved domain, which had been implicated in coordinating COPII assembly, is actually dispensable for normal tER structure. An upstream conserved region (UCR) localizes Sec16 to tER sites. The UCR binds COPII components, and removal of COPII from tER sites also removes Sec16, indicating that COPII recruits Sec16 rather than the other way around. We propose that Sec16 does not in fact organize COPII. Instead, regulation of COPII turnover can account for the influence of Sec16 on tER sites.
PDB ID: 4L9ODownload
MMDB ID: 114094
PDB Deposition Date: 2013/6/18
Updated in MMDB: 2013/10
Experimental Method:
x-ray diffraction
Resolution: 1.6  Å
Similar Structures:
Biological Unit for 4L9O: monomeric; determined by author and by software (PISA)
Molecular Components in 4L9O
Label Count Molecule
Protein (1 molecule)
Sec16,protein Transport Protein Sec13(Gene symbol: PAS_chr1-3_0057)
Molecule annotation
Chemicals (9 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB