Chapter category: Chaperones
The Roles of GroES As a Co-Chaperone for GroEL
Networking of Chaperones
by Co-Chaperones
Edited by: Gregory L. BlatchISBN: 978-0-387-49308-4
» Get more information about this book at landesbioscience.com «
Chapter authors:
Han Liu and Peter A Lund
GroES works with the essential chaperone GroEL to mediate the folding of certain proteins from an unfolded or partially folded state. These two proteins form the only essential chaperone machine in E. coli. Both proteins have seven-fold symmetry. GroES acts by binding to one end of the GroEL complex in the presence of nucleotide. In doing this, it has several roles. It displaces bound substrate protein from GroEL into the folding cavity within the GroEL complex, and caps it while the protein folds. It also helps mediate the allosteric transitions that the GroEL complex undergoes during the course of its reaction cycle. A key part of the GroES co-chaperone is an extended loop of amino-acids that is highly mobile when the protein is free but becomes ordered on binding to GroEL, and the interaction between this mobile loop and GroEL helps define both the strength of the binding and the speed with which the chaperone machine passes through its cycle.
Additional chapters from this book:
The Chaperone and Co-Chaperone Activities of Cdc37 during Protein Kinase Maturation
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Eukaryotic protein kinases fold in the cytosol in association with the Hsp90 molecular chaperone machine. This machine comprises a large number of chaperones and co-chaperones, among them Cdc37,...
Hop: An Hsp70/Hsp90 Co-Chaperone That Functions within and beyond Hsp70/Hsp90 Protein Folding Pathways
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Molecular chaperones and their co-chapterones are crucial for the facilitation of efficient protein folding, and prevention of denaturation and aggregation of nascent polypeptides. Hsp70/Hsp90 o...
The Roles of GroES As a Co-Chaperone for GroEL
Han Liu and Peter A Lund
GroES works with the essential chaperone GroEL to mediate the folding of certain proteins from an unfolded or partially folded state. These two proteins form the only essential chaperone machine...
The Role of Hsp70 and Its Co-Chaperones in Protein Misfolding, Aggregation and Disease
Jacqueline van der Spuy, Michael E. Cheetham and J. Paul Chapple
Molecular chaperones and their associated co-chaperones are essential in health and disease as they are key facilitators of protein folding, quality control and function. In particular, the Hsp7...
Do Hsp40s Act As Chaperones or Co-Chaperones?
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The Hsp70 family plays an essential role in cellular protein metabolism by acting as a polypeptide binding and release factor that interacts with nonnative regions of proteins at different stage...
UNC-45: A Chaperone for Myosin and a Co-Chaperone for Hsp90
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UNC-45 is a prototype of the protein family characterized by the presence of the C-terminal UCS (UNC-45/CRO1/She4p) domain. These proteins function in vari- ous important actin- and myosin-depend...
The Evolution and Function of Co-Chaperones in Mitochondria
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Mitochondrial chaperones mediate and affect critical organellar processes, essential for cellular function. These chaperone systems have both prokaryotic and eukaryotic features. While some of t...
From Creator to Terminator: Co-Chaperones That Link Molecular Chaperones to the Ubiquitin/Proteasome System
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Molecular chaperones are well known as intracellular mediators of protein folding. An active participation in protein degradation only recently emerged from the functional characterization of cert...
Co-Chaperones of the Endoplasmic Reticulum
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The rough endoplasmic reticulum (ER) plays a central role in the biogenesis of most extracellular and many organellar proteins in eukaryotic cells. Therefore, this organelle comprises molecular ch...
Functions of the Hsp90-Binding FKBP Immunophilins
Marc B. Cox and David F. Smith
Hsp90 functionally interacts with a broad array of client proteins, but in every case examined Hsp90 is accompanied by one or more cochaperones. One class of cochaperone contains a tetratricopeptide...
Nucleotide Exchange Factors for Hsp70 Molecular Chaperones
Jeffrey L. Brodsky and Andreas Bracher
Hsp70 molecular chaperones hydrolyze and re-bind ATP concomitant with the binding and release of aggregation-prone protein substrates. As a result, Hsp70s can enhance protein folding and degradation...
