Andersson, Marlene
- Department of Animal Biosciences, Swedish University of Agricultural Sciences
Abstract
The mechanisms controlling the conversion of spider silk proteins into insoluble fibres, which happens in a fraction of a second and in a defined region of the silk glands, are still unresolved. The N-terminal domain changes conformation and forms a homodimer when pH is lowered from 7 to 6; however, the molecular details still remain to be determined. Here we investigate site-directed mutants of the N-terminal domain from Euprosthenops australis major ampullate spidroin 1 and find that the charged residues D40, R60 and K65 mediate intersubunit electrostatic interactions. Protonation of E79 and E119 is required for structural conversions of the subunits into a dimer conformation, and subsequent protonation of E84 around pH 5.7 leads to the formation of a fully stable dimer. These residues are highly conserved, indicating that the now proposed three-step mechanism prevents premature aggregation of spidroins and enables fast formation of spider silk fibres in general.
Published in
Nature Communications
2014, volume: 5
Publisher: NATURE PUBLISHING GROUP
SLU Authors
Rising, Anna
- Department of Animal Biosciences, Swedish University of Agricultural Sciences
- Department of Animal Biosciences, Swedish University of Agricultural Sciences
Johansson, Jan
- Department of Animal Biosciences, Swedish University of Agricultural Sciences
- Department of Animal Biosciences, Swedish University of Agricultural Sciences
UKÄ Subject classification
Biochemistry
Structural Biology
Molecular Biology
Publication identifier
- DOI: https://doi.org/10.1038/ncomms4254
Permanent link to this page (URI)
https://res.slu.se/id/publ/53204