5F44

Crystal structure of shaft pilin spaA from Lactobacillus rhamnosus GG

5F44 の概要

• エントリーDOI: 10.2210/pdb5f44/pdb
• 関連するPDBエントリー: 5FAA 5FGR 5FGS 5FIE 5HBB 5HDL 5HTS 5J4M
• 分子名称: Cell surface protein SpaA, ACETATE ION (3 entities in total)
• 機能のキーワード: pilin, spaa, probiotic, isopeptide, spacba pili, adhesin, cell adhesion
• 由来する生物種: Lactobacillus rhamnosus GG
• タンパク質・核酸の鎖数: 3
• 化学式量合計: 92347.63

構造登録者

Chaurasia, P.,Pratap, S.,von Ossowski, I.,Palva, A.,Krishnan, V. (登録日: 2015-12-03, 公開日: 2016-07-20, 最終更新日: 2024-10-16)

主引用文献

Chaurasia, P.,Pratap, S.,von Ossowski, I.,Palva, A.,Krishnan, V.
New insights about pilus formation in gut-adapted Lactobacillus rhamnosus GG from the crystal structure of the SpaA backbone-pilin subunit
Sci Rep, 6:28664-28664, 2016

PubMed Abstract: Thus far, all solved structures of pilin-proteins comprising sortase-assembled pili are from pathogenic genera and species. Here, we present the first crystal structure of a pilin subunit (SpaA) from a non-pathogen host (Lactobacillus rhamnosus GG). SpaA consists of two tandem CnaB-type domains, each with an isopeptide bond and E-box motif. Intriguingly, while the isopeptide bond in the N-terminal domain forms between lysine and asparagine, the one in the C-terminal domain atypically involves aspartate. We also solved crystal structures of mutant proteins where residues implicated in forming isopeptide bonds were replaced. Expectedly, the E-box-substituted E139A mutant lacks an isopeptide bond in the N-terminal domain. However, the C-terminal E269A substitution gave two structures; one of both domains with their isopeptide bonds present, and another of only the N-terminal domain, but with an unformed isopeptide bond and significant conformational changes. This latter crystal structure has never been observed for any other Gram-positive pilin. Notably, the C-terminal isopeptide bond still forms in D295N-substituted SpaA, irrespective of E269 being present or absent. Although E-box mutations affect SpaA proteolytic and thermal stability, a cumulative effect perturbing normal pilus polymerization was unobserved. A model showing the polymerized arrangement of SpaA within the SpaCBA pilus is proposed.

PubMed: 27349405
DOI: 10.1038/srep28664

実験手法

X-RAY DIFFRACTION (1.904 Å)