8QB1

C-terminal domain of mirolase from Tannerella forsythia

Summary for 8QB1

• Entry DOI: 10.2210/pdb8qb1/pdb
• Descriptor: Mirolase, CHLORIDE ION, DI(HYDROXYETHYL)ETHER, ... (5 entities in total)
• Functional Keywords: type-ix secretion system c-terminal secretion-signal domain, protein transport
• Biological source: Tannerella forsythia
• Total number of polymer chains: 6
• Total formula weight: 60501.08

Authors

Gomis-Ruth, F.X.,Rodriguez-Banqueri, A.,Mizgalska, D.,Veillard, F.,Goulas, T.,Eckhard, U.,Potempa, J. (deposition date: 2023-08-23, release date: 2024-02-28, Last modification date: 2024-10-16)

Primary citation

Mizgalska, D.,Rodriguez-Banqueri, A.,Veillard, F.,Ksiazek, M.,Goulas, T.,Guevara, T.,Eckhard, U.,Potempa, J.,Gomis-Ruth, F.X.
Structural and functional insights into the C-terminal signal domain of the Bacteroidetes type-IX secretion system.
Open Biology, 14:230448-230448, 2024

PubMed Abstract: Gram-negative bacteria from the Bacteroidota phylum possess a type-IX secretion system (T9SS) for protein secretion, which requires cargoes to have a C-terminal domain (CTD). Structurally analysed CTDs are from proteins RgpB, HBP35, PorU and PorZ, which share a compact immunoglobulin-like antiparallel 3+4 β-sandwich (β1-β7). This architecture is essential as a strain with a single-point mutant of RgpB disrupting the interaction of the CTD with its preceding domain prevented secretion of the protein. Next, we identified the C-terminus ('motif C-t.') and the loop connecting strands β3 and β4 ('motif Lβ3β4') as conserved. We generated two strains with insertion and replacement mutants of PorU, as well as three strains with ablation and point mutants of RgpB, which revealed both motifs to be relevant for T9SS function. Furthermore, we determined the crystal structure of the CTD of mirolase, a cargo of the T9SS which shares the same general topology as in CTDs. However, motif Lβ3β4 was not conserved. Consistently, could not properly secrete a chimaeric protein with the CTD of peptidylarginine deiminase replaced with this foreign CTD. Thus, the incompatibility of the CTDs between these species prevents potential interference between their T9SSs.

PubMed: 38862016
DOI: 10.1098/rsob.230448

Experimental method

X-RAY DIFFRACTION (1.601 Å)