Network of Entamoeba histolytica HSP18.5 dimers formed by two overlapping [IV]-X-[IV] motifs
| Autor: | Kaza Suguna, Devanshu Kurre |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
0303 health sciences
biology Chemistry 030302 biochemistry & molecular biology Crystal structure biology.organism_classification Biochemistry Negative stain Crystal 03 medical and health sciences Crystallography Entamoeba histolytica Tetramer Structural Biology Heat shock protein Molecule Molecular Biology Dynamic equilibrium 030304 developmental biology |
| Zdroj: | ProteinsREFERENCES. |
| ISSN: | 1097-0134 |
| Popis: | Small heat shock proteins (sHSPs) are ATP-independent molecular chaperones with low molecular weight that prevent the aggregation of proteins during stress conditions and maintain protein homeostasis in the cell. sHSPs exist in dynamic equilibrium as a mixture of oligomers of various sizes with a constant exchange of subunits between them. Many sHSPs form cage-like assemblies that may dissociate into smaller oligomers during stress conditions. We carried out the functional and structural characterization of a small heat shock protein, HSP18.5, from Entamoeba histolytica (EhHSP18.5). It showed a pH-dependent change in its oligomeric state, which varied from a tetramer to larger than 48-mer. EhHSP18.5 protected Nde I and lysozyme substrates from temperature and chemical stresses, respectively. The crystal structure of EhHSP18.5 was determined at a resolution of 3.28 a in C2221 cell with four subunits in the asymmetric unit forming two non-metazoan sHSP-type dimers. Unlike the reported cage-like structures, EhHSP18.5 formed a network of linear chains of molecules in the crystal. Instead of a single [IV]-X-[IV] motif, EhHSP18.5 has two overlapping I/V-X-I/V sequences at the C-terminus giving rise to novel interactions between the dimers. Negative staining Electron Microscopy images of EhHSP18.5 showed the presence of multiple oligomers: closed structures of various sizes and long tube-like structures. This article is protected by copyright. All rights reserved. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Plný text