2QTV

Structure of Sec23-Sar1 complexed with the active fragment of Sec31

Summary for 2QTV

• Entry DOI: 10.2210/pdb2qtv/pdb
• Descriptor: Protein transport protein SEC23, Small COPII coat GTPase SAR1, Protein transport protein SEC31, ... (7 entities in total)
• Functional Keywords: copii coat, vesicular transport, cytoplasm, cytoplasmic vesicle, endoplasmic reticulum, er-golgi transport, golgi apparatus, membrane, metal-binding, protein transport, ubl conjugation, zinc, gtp-binding, hydrolase, nucleotide-binding, phosphorylation, wd repeat
• Biological source: Saccharomyces cerevisiae (baker's yeast); More
• Cellular location: Cytoplasmic vesicle, COPII-coated vesicle membrane ; Peripheral membrane protein ; Cytoplasmic side : P15303 P20606 P38968
• Total number of polymer chains: 3
• Total formula weight: 110399.84

Authors

Goldberg, J.,Bi, X.,Mancias, J.D. (deposition date: 2007-08-02, release date: 2008-01-15, Last modification date: 2024-02-21)

Primary citation

Bi, X.,Mancias, J.D.,Goldberg, J.
Insights into COPII coat nucleation from the structure of Sec23.Sar1 complexed with the active fragment of Sec31.
Dev.Cell, 13:635-645, 2007

PubMed Abstract: The COPII vesicular coat forms on the endoplasmic reticulum from Sar1-GTP, Sec23/24 and Sec13/31 protein subunits. Here, we define the interaction between Sec23/24.Sar1 and Sec13/31, involving a 40 residue Sec31 fragment. In the crystal structure of the ternary complex, Sec31 binds as an extended polypeptide across a composite surface of the Sec23 and Sar1-GTP molecules, explaining the stepwise character of Sec23/24.Sar1 and Sec13/31 recruitment to the membrane. The Sec31 fragment stimulates GAP activity of Sec23/24, and a convergence of Sec31 and Sec23 residues at the Sar1 GTPase active site explains how GTP hydrolysis is triggered leading to COPII coat disassembly. The Sec31 active fragment is accommodated in a binding groove supported in part by Sec23 residue Phe380. Substitution of the corresponding residue F382L in human Sec23A causes cranio-lenticulo-sutural dysplasia, and we suggest that this mutation disrupts the nucleation of COPII coat proteins at endoplasmic reticulum exit sites.

PubMed: 17981133
DOI: 10.1016/j.devcel.2007.10.006

Experimental method

X-RAY DIFFRACTION (2.5 Å)