8CUE

CryoEM structure of the T-pilus from Agrobacterium tumefaciens

This is a non-PDB format compatible entry.

Summary for 8CUE

• Entry DOI: 10.2210/pdb8cue/pdb
• EMDB information: 26999
• Descriptor: Protein virB2, 1-PALMITOYL-2-LINOLEOYL-SN-GLYCERO-3-PHOSPHOCHOLINE (2 entities in total)
• Functional Keywords: conjugation, virb2, type iv secretion system, pili, structural protein
• Biological source: Agrobacterium fabrum (strain C58 / ATCC 33970)
• Total number of polymer chains: 70
• Total formula weight: 915914.93

Authors

Bui, K.H.,Black, C.S. (deposition date: 2022-05-17, release date: 2023-02-01, Last modification date: 2024-04-17)

Primary citation

Amro, J.,Black, C.,Jemouai, Z.,Rooney, N.,Daneault, C.,Zeytuni, N.,Ruiz, M.,Bui, K.H.,Baron, C.
Cryo-EM structure of the Agrobacterium tumefaciens T-pilus reveals the importance of positive charges in the lumen.
Structure, 31:375-384.e4, 2023

PubMed Abstract: Agrobacterium tumefaciens is a natural genetic engineer that transfers DNA into plants, which is the most applied process for generation of genetically modified plants. DNA transfer is mediated by a type IV secretion system in the cell envelope and extracellular T-pili. We here report the cryo-electron microscopic structures of the T-pilus at 3.2-Å resolution and of the plasmid pKM101-determined N-pilus at 3-Å resolution. Both pili contain a main pilus protein (VirB2 in A. tumefaciens, TraM in pKM101) and phospholipids arranged in a five-start helical assembly. They contain positively charged amino acids in the lumen, and the lipids are positively charged in the T-pilus (phosphatidylcholine) conferring overall positive charge. Mutagenesis of the lumen-exposed Arg91 in VirB2 results in protein destabilization and loss of pilus formation. Our results reveal that different phospholipids can be incorporated into type IV secretion pili and that the charge of the lumen may be of functional importance.

PubMed: 36513067
DOI: 10.1016/j.str.2022.11.007

Experimental method

ELECTRON MICROSCOPY (3.2 Å)