8US3

C2 Crystal structure of TamA from Pseudomonas aeruginosa at 3.1 Ang

8US3 の概要

• エントリーDOI: 10.2210/pdb8us3/pdb
• 分子名称: Translocation and assembly module subunit TamA, (HYDROXYETHYLOXY)TRI(ETHYLOXY)OCTANE, MAGNESIUM ION, ... (4 entities in total)
• 機能のキーワード: omp85, protein translocation, membrane protein
• 由来する生物種: Pseudomonas aeruginosa
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 61982.69

構造登録者

Mellouk, A.,Moraes, T.F.,Calmettes, C. (登録日: 2023-10-27, 公開日: 2024-06-26, 最終更新日: 2024-07-17)

主引用文献

Mellouk, A.,Jaouen, P.,Ruel, L.J.,Le, M.,Martini, C.,Moraes, T.F.,El Bakkouri, M.,Lague, P.,Boisselier, E.,Calmettes, C.
POTRA domains of the TamA insertase interact with the outer membrane and modulate membrane properties.
Proc.Natl.Acad.Sci.USA, 121:e2402543121-e2402543121, 2024

PubMed Abstract: The outer membrane (OM) of gram-negative bacteria serves as a vital organelle that is densely populated with OM proteins (OMPs) and plays pivotal roles in cellular functions and virulence. The assembly and insertion of these OMPs into the OM represent a fundamental process requiring specialized molecular chaperones. One example is the translocation and assembly module (TAM), which functions as a transenvelope chaperone promoting the folding of specific autotransporters, adhesins, and secretion systems. The catalytic unit of TAM, TamA, comprises a catalytic β-barrel domain anchored within the OM and three periplasmic polypeptide-transport-associated (POTRA) domains that recruit the TamB subunit. The latter acts as a periplasmic ladder that facilitates the transport of unfolded OMPs across the periplasm. In addition to their role in recruiting the auxiliary protein TamB, our data demonstrate that the POTRA domains mediate interactions with the inner surface of the OM, ultimately modulating the membrane properties. Through the integration of X-ray crystallography, molecular dynamic simulations, and biomolecular interaction methodologies, we located the membrane-binding site on the first and second POTRA domains. Our data highlight a binding preference for phosphatidylglycerol, a minor lipid constituent present in the OM, which has been previously reported to facilitate OMP assembly. In the context of the densely OMP-populated membrane, this association may serve as a mechanism to secure lipid accessibility for nascent OMPs through steric interactions with existing OMPs, in addition to creating favorable conditions for OMP biogenesis.

PubMed: 38959031
DOI: 10.1073/pnas.2402543121

実験手法

X-RAY DIFFRACTION (3.1 Å)