9FSM

Cryo-EM structure of the decameric TraT surface exclusion lipoprotein from Klebsiella pneumoniae (pKpQIL plasmid)

Summary for 9FSM

• Entry DOI: 10.2210/pdb9fsm/pdb
• EMDB information: 50728
• Descriptor: TraT complement resistance protein, DIACYL GLYCEROL (2 entities in total)
• Functional Keywords: surface exclusion, decamer, diacylglycerol (dag) modification, membrane protein
• Biological source: Klebsiella pneumoniae
• Total number of polymer chains: 10
• Total formula weight: 246149.83

Authors

Seddon, C.,Beis, K. (deposition date: 2024-06-21, release date: 2024-12-11, Last modification date: 2025-06-11)

Primary citation

Seddon, C.,David, S.,Wong, J.L.C.,Ishimoto, N.,He, S.,Bradshaw, J.,Low, W.W.,Frankel, G.,Beis, K.
Cryo-EM structure and evolutionary history of the conjugation surface exclusion protein TraT.
Nat Commun, 16:659-659, 2025

PubMed Abstract: Conjugation plays a major role in dissemination of antimicrobial resistance genes. Following transfer of IncF-like plasmids, recipients become refractory to a second wave of conjugation with the same plasmid via entry (TraS) and surface (TraT) exclusion mechanisms. Here, we show that TraT from the pKpQIL and F plasmids (TraT and TraT) exhibits plasmid surface exclusion specificity. The cryo-EM structures of TraT and TraT reveal that they oligomerise into decameric champagne bottle cork-like structures, which are anchored to the outer membrane via a diacylglycerol and palmitic acid modified α-helical barrel domain. Unexpectedly, we identify chromosomal TraT homologues from multiple Gram-negative phyla which form numerous divergent lineages in a phylogenetic tree of TraT sequences. Plasmid-associated TraT sequences are found in multiple distinct lineages, including two separate clades incorporating TraT from Enterobacteriaceae IncF/F-like and Legionellaceae F-like plasmids. These findings suggest that different plasmid backbones have acquired and co-opted TraT on independent occasions.

PubMed: 39809778
DOI: 10.1038/s41467-025-55834-w

Experimental method

ELECTRON MICROSCOPY (2.47 Å)