8CO1

Type II Secretion System

This is a non-PDB format compatible entry.

Summary for 8CO1

• Entry DOI: 10.2210/pdb8co1/pdb
• EMDB information: 16770
• Descriptor: Probable type IV piliation system protein DR_0774, IPT/TIG domain-containing protein, Lipoprotein (3 entities in total)
• Functional Keywords: type ii secretion system, membrane protein, cell envelope
• Biological source: Deinococcus radiodurans R1 = ATCC 13939 = DSM 20539; More
• Total number of polymer chains: 45
• Total formula weight: 1746336.48

Authors

Farci, D.,Piano, D. (deposition date: 2023-02-26, release date: 2024-04-10, Last modification date: 2025-07-09)

Primary citation

Farci, D.,Milenkovic, S.,Iesu, L.,Tanas, M.,Ceccarelli, M.,Piano, D.
Structural characterization and functional insights into the type II secretion system of the poly-extremophile Deinococcus radiodurans.
J.Biol.Chem., 300:105537-105537, 2024

PubMed Abstract: The extremophile bacterium D. radiodurans boasts a distinctive cell envelope characterized by the regular arrangement of three protein complexes. Among these, the Type II Secretion System (T2SS) stands out as a pivotal structural component. We used cryo-electron microscopy to reveal unique features, such as an unconventional protein belt (DR_1364) around the main secretin (GspD), and a cap (DR_0940) found to be a separated subunit rather than integrated with GspD. Furthermore, a novel region at the N-terminus of the GspD constitutes an additional second gate, supplementing the one typically found in the outer membrane region. This T2SS was found to contribute to envelope integrity, while also playing a role in nucleic acid and nutrient trafficking. Studies on intact cell envelopes show a consistent T2SS structure repetition, highlighting its significance within the cellular framework.

PubMed: 38072042
DOI: 10.1016/j.jbc.2023.105537

Experimental method

ELECTRON MICROSCOPY (2.56 Å)