5T10

PelC dodecamer from Paraburkholderia phytofirmans, space group P6

5T10 の概要

• エントリーDOI: 10.2210/pdb5t10/pdb
• 分子名称: Uncharacterized protein (2 entities in total)
• 機能のキーワード: lipoprotein, periplasmic, structural protein
• 由来する生物種: Paraburkholderia phytofirmans
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 67222.19

構造登録者

Marmont, L.S.,Howell, P.L. (登録日: 2016-08-17, 公開日: 2017-03-15, 最終更新日: 2023-10-04)

主引用文献

Marmont, L.S.,Rich, J.D.,Whitney, J.C.,Whitfield, G.B.,Almblad, H.,Robinson, H.,Parsek, M.R.,Harrison, J.J.,Howell, P.L.
Oligomeric lipoprotein PelC guides Pel polysaccharide export across the outer membrane of Pseudomonas aeruginosa.
Proc. Natl. Acad. Sci. U.S.A., 114:2892-2897, 2017

PubMed Abstract: Secreted polysaccharides are important functional and structural components of bacterial biofilms. The opportunistic pathogen produces the cationic exopolysaccharide Pel, which protects bacteria from aminoglycoside antibiotics and contributes to biofilm architecture through ionic interactions with extracellular DNA. A bioinformatics analysis of genome databases suggests that gene clusters for Pel biosynthesis are present in >125 bacterial species, yet little is known about how this biofilm exopolysaccharide is synthesized and exported from the cell. In this work, we characterize PelC, an outer membrane lipoprotein essential for Pel production. Crystal structures of PelC from and coupled with structure-guided disulfide cross-linking in suggest that PelC assembles into a 12- subunit ring-shaped oligomer. In this arrangement, an aromatic belt in proximity to its lipidation site positions the highly electronegative surface of PelC toward the periplasm. PelC is structurally similar to the amyloid exporter CsgG; however, unlike CsgG, PelC does not possess membrane-spanning segments required for polymer export across the outer membrane. We show that the multidomain protein PelB with a predicted C-terminal β-barrel porin localizes to the outer membrane, and propose that PelC functions as an electronegative funnel to guide the positively charged Pel polysaccharide toward an exit channel formed by PelB. Together, our findings provide insight into the unique molecular architecture and export mechanism of the Pel apparatus, a widespread exopolysaccharide secretion system found in environmental and pathogenic bacteria.

PubMed: 28242707
DOI: 10.1073/pnas.1613606114

実験手法

X-RAY DIFFRACTION (2.4987 Å)