Fibrillation of the major curli subunit CsgA under a wide range of conditions implies a robust design of aggregation

TY - JOUR

T1 - Fibrillation of the major curli subunit CsgA under a wide range of conditions implies a robust design of aggregation

AU - Dueholm, Morten S

AU - Nielsen, Søren Bang

AU - Hein, Kim L

AU - Nissen, Poul

AU - Chapman, Matthew

AU - Christiansen, Gunna

AU - Nielsen, Per Halkjær

AU - Otzen, Daniel E

PY - 2011

Y1 - 2011

N2 - The amyloid fold is usually considered a result of protein misfolding. However, a number of studies have recently shown that the amyloid structure is also used in nature for functional purposes. CsgA is the major subunit of Escherichia coli curli, one of the most well-characterized functional amyloids. Here we show, using a highly efficient approach to prepare monomeric CsgA, that in vitro fibrillation of CsgA occurs under a wide variety of environmental conditions and that the resulting fibrils exhibit similar structural features. This highlights how fibrillation is "hardwired" into amyloid that has evolved for structural purposes in a fluctuating extracellular environment and represents a clear contrast to disease-related amyloid formation. Furthermore, we show that CsgA polymerization in vitro is preceded by the formation of thin needlelike protofibrils followed by aggregation of the amyloid fibrils.

AB - The amyloid fold is usually considered a result of protein misfolding. However, a number of studies have recently shown that the amyloid structure is also used in nature for functional purposes. CsgA is the major subunit of Escherichia coli curli, one of the most well-characterized functional amyloids. Here we show, using a highly efficient approach to prepare monomeric CsgA, that in vitro fibrillation of CsgA occurs under a wide variety of environmental conditions and that the resulting fibrils exhibit similar structural features. This highlights how fibrillation is "hardwired" into amyloid that has evolved for structural purposes in a fluctuating extracellular environment and represents a clear contrast to disease-related amyloid formation. Furthermore, we show that CsgA polymerization in vitro is preceded by the formation of thin needlelike protofibrils followed by aggregation of the amyloid fibrils.

KW - Adhesins, Bacterial

KW - Amyloid

KW - Bacterial Proteins

KW - Escherichia coli

KW - Escherichia coli Proteins

KW - Hydrogen-Ion Concentration

KW - Osmolar Concentration

KW - Protein Structure, Quaternary

U2 - 10.1021/bi200967c

DO - 10.1021/bi200967c

M3 - Journal article

C2 - 21877724

SN - 0006-2960

VL - 50

SP - 8281

EP - 8290

JO - Biochemistry

JF - Biochemistry

IS - 39

ER -