8C8M

In vitro structure of the Nitrosopumilus maritimus S-layer - Composite map between two and six-fold symmetrised

8C8M の概要

• エントリーDOI: 10.2210/pdb8c8m/pdb
• EMDBエントリー: 16482 16483 16484
• 分子名称: Cell surface protein (1 entity in total)
• 機能のキーワード: nmar_1547 s-layer, structural protein
• 由来する生物種: Nitrosopumilus maritimus SCM1
• タンパク質・核酸の鎖数: 6
• 化学式量合計: 1098936.00

構造登録者

von Kuegelgen, A.,Bharat, T. (登録日: 2023-01-20, 公開日: 2024-04-10, 最終更新日: 2024-10-16)

主引用文献

von Kugelgen, A.,Cassidy, C.K.,van Dorst, S.,Pagani, L.L.,Batters, C.,Ford, Z.,Lowe, J.,Alva, V.,Stansfeld, P.J.,Bharat, T.A.M.
Membraneless channels sieve cations in ammonia-oxidizing marine archaea.
Nature, 630:230-236, 2024

PubMed Abstract: Nitrosopumilus maritimus is an ammonia-oxidizing archaeon that is crucial to the global nitrogen cycle. A critical step for nitrogen oxidation is the entrapment of ammonium ions from a dilute marine environment at the cell surface and their subsequent channelling to the cell membrane of N. maritimus. Here we elucidate the structure of the molecular machinery responsible for this process, comprising the surface layer (S-layer), using electron cryotomography and subtomogram averaging from cells. We supplemented our in situ structure of the ammonium-binding S-layer array with a single-particle electron cryomicroscopy structure, revealing detailed features of this immunoglobulin-rich and glycan-decorated S-layer. Biochemical analyses showed strong ammonium binding by the cell surface, which was lost after S-layer disassembly. Sensitive bioinformatic analyses identified similar S-layers in many ammonia-oxidizing archaea, with conserved sequence and structural characteristics. Moreover, molecular simulations and structure determination of ammonium-enriched specimens enabled us to examine the cation-binding properties of the S-layer, revealing how it concentrates ammonium ions on its cell-facing side, effectively acting as a multichannel sieve on the cell membrane. This in situ structural study illuminates the biogeochemically essential process of ammonium binding and channelling, common to many marine microorganisms that are fundamental to the nitrogen cycle.

PubMed: 38811725
DOI: 10.1038/s41586-024-07462-5

実験手法

ELECTRON MICROSCOPY (2.87 Å)