TY - JOUR
T1 - FapA is an Intrinsically Disordered Chaperone for Pseudomonas Functional Amyloid FapC
AU - Rasmussen, Helena Ø
AU - Kumar, Amit
AU - Shin, Ben
AU - Stylianou, Fisentzos
AU - Sewell, Lee
AU - Xu, Yingqi
AU - Otzen, Daniel E
AU - Pedersen, Jan Skov
AU - Matthews, Steve J
PY - 2023/1
Y1 - 2023/1
N2 - Bacterial functional amyloids contribute to biofilm development by bacteria and provide protection from the immune system and prevent antibiotic treatment. Strategies to target amyloid formation and interrupt biofilm formation have attracted recent interest due to their antimicrobial potential. Functional amyloid in Pseudomonas (Fap) includes FapC as the major component of the fibril while FapB is a minor component suggested to function as a nucleator of FapC. The system also includes the small periplasmic protein FapA, which has been shown to regulate fibril composition and morphology. The interplay between these three components is central in Fap fibril biogenesis. Here we present a comprehensive biophysical and spectroscopy analysis of FapA, FapB and FapC and provide insight into their molecular interactions. We show that all three proteins are primarily disordered with some regions with structural propensities for α-helix and β-sheet. FapA inhibits FapC fibrillation by targeting the nucleation step, whereas for FapB the elongation step is modulated. Furthermore, FapA alters the morphology of FapC (more than FapB) fibrils. Complex formation is observed between FapA and FapC, but not between FapA and FapB, and likely involves the N-terminus of FapA. We conclude that FapA is an intrinsically disordered chaperone for FapC that guards against fibrillation within the periplasm. This new understanding of a natural protective mechanism of Pseudomonas against amyloid formations can serve as inspiration for strategies blocking biofilm formation in infections.
AB - Bacterial functional amyloids contribute to biofilm development by bacteria and provide protection from the immune system and prevent antibiotic treatment. Strategies to target amyloid formation and interrupt biofilm formation have attracted recent interest due to their antimicrobial potential. Functional amyloid in Pseudomonas (Fap) includes FapC as the major component of the fibril while FapB is a minor component suggested to function as a nucleator of FapC. The system also includes the small periplasmic protein FapA, which has been shown to regulate fibril composition and morphology. The interplay between these three components is central in Fap fibril biogenesis. Here we present a comprehensive biophysical and spectroscopy analysis of FapA, FapB and FapC and provide insight into their molecular interactions. We show that all three proteins are primarily disordered with some regions with structural propensities for α-helix and β-sheet. FapA inhibits FapC fibrillation by targeting the nucleation step, whereas for FapB the elongation step is modulated. Furthermore, FapA alters the morphology of FapC (more than FapB) fibrils. Complex formation is observed between FapA and FapC, but not between FapA and FapB, and likely involves the N-terminus of FapA. We conclude that FapA is an intrinsically disordered chaperone for FapC that guards against fibrillation within the periplasm. This new understanding of a natural protective mechanism of Pseudomonas against amyloid formations can serve as inspiration for strategies blocking biofilm formation in infections.
KW - Amyloid/chemistry
KW - Bacterial Proteins/chemistry
KW - Biofilms
KW - Intrinsically Disordered Proteins/chemistry
KW - Molecular Chaperones/chemistry
KW - Pseudomonas/metabolism
UR - http://www.scopus.com/inward/record.url?scp=85142873219&partnerID=8YFLogxK
U2 - 10.1016/j.jmb.2022.167878
DO - 10.1016/j.jmb.2022.167878
M3 - Journal article
C2 - 36368411
SN - 0022-2836
VL - 435
JO - Journal of Molecular Biology
JF - Journal of Molecular Biology
IS - 2
M1 - 167878
ER -