Diversified Structural Basis of a Conserved Molecular Mechanism for pH-Dependent Dimerization in Spider Silk N-Terminal Domains
Conversion of spider silk proteins from soluble dope to insoluble fibers involves pH‐dependent dimerization of the N‐terminal domain (NT). This conversion is tightly regulated to prevent premature precipitation and enable rapid silk formation at the end of the duct. Three glutamic acid residues that...
Saved in:
Published in | Chembiochem : a European journal of chemical biology Vol. 16; no. 12; pp. 1720 - 1724 |
---|---|
Main Authors | , , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Weinheim
WILEY-VCH Verlag
17.08.2015
WILEY‐VCH Verlag Wiley Subscription Services, Inc |
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | Conversion of spider silk proteins from soluble dope to insoluble fibers involves pH‐dependent dimerization of the N‐terminal domain (NT). This conversion is tightly regulated to prevent premature precipitation and enable rapid silk formation at the end of the duct. Three glutamic acid residues that mediate this process in the NT from Euprosthenops australis major ampullate spidroin 1 are well conserved among spidroins. However, NTs of minor ampullate spidroins from several species, including Araneus ventricosus (AvMiSp NT), lack one of the glutamic acids. Here we investigate the pH‐dependent structural changes of AvMiSp NT, revealing that it uses the same mechanism but involves a non‐conserved glutamic acid residue instead. Homology modeling of the structures of other MiSp NTs suggests that these harbor different compensatory residues. This indicates that, despite sequence variations, the molecular mechanism underlying pH‐dependent dimerization of NT is conserved among different silk types.
Spinning webs: Conversion of spider silk proteins from soluble dope to insoluble fibers involves pH‐dependent dimerization of the N‐terminal domain (NT). We have analyzed the pH dependence of the A. ventricosus minor ampullate spidroin NT and determined solution structures at pH 7.2 and 5.5, revealing that the dimerization is mediated by protonation of three glutamic acid residues. |
---|---|
Bibliography: | ark:/67375/WNG-J85PF8Q3-6 ArticleID:CBIC201500263 State Administration of Foreign Experts Affairs of China - No. 20120075110007; No. TS2011DHDX025; No. 14521100700; No. 14520720200; No. GDW20143100070 istex:9BA1E418ABBF0B79E01A0C9E77DD48C7B88D1B07 These authors contributed equally to this work. ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 1439-4227 1439-7633 1439-7633 |
DOI: | 10.1002/cbic.201500263 |