Molecular Playground/Hsp70-Hsp90: Difference between revisions
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<Structure load='Insert PDB code or filename here' size='500' frame='true' align='right' caption='ERdj5 [[3apo]]' scene='User:Lydia_Lamriben/Sandbox1/Thioredoxin-like_domains/4' /> | <Structure load='Insert PDB code or filename here' size='500' frame='true' align='right' caption='ERdj5 [[3apo]]' scene='User:Lydia_Lamriben/Sandbox1/Thioredoxin-like_domains/4' /> | ||
== | ==Hsp70-Hsp90 Organizing Protein (Hop)== | ||
Hop is an adaptor protein which mediates the association of the molecular chaperones Hsp70 and Hsp90 as some proteins require their coordinated activities for folding and conformational regulation. Hsp90 receives its substrates from Hsp70 in a reaction that is critically dependent on Hop, but how Hop mediates this hand-off was unclear until structural studies of Hop were conducted. Hop is not a chaperone itself, and it is composed almost entirely of Tetra-trico-peptide repeat (TPR) domains. TPR domains are defined as multiple repeats of 34 amino acids that share a degenerate consensus sequence consisting of a pattern of small and large hydrophobic amino acids, with no position being completely invariant. TPR domains are found in many proteins and often serve as interaction modules in multiprotein complexes. | |||
==TPR Domain 1 Structure== | ==TPR Domain 1 Structure== | ||
<scene name='User:Lydia_Lamriben/Sandbox1/Erdj5/1'>ERdj5</scene> is an Endoplasmic Reticulum (ER) resident protein disulfide isomerase. It is a 793 amino acid multi-domain protein. It consists of an N-terminal <scene name='User:Lydia_Lamriben/Sandbox1/J-domain/4'>J-domain</scene> that has been shown to bind to BIP, ER resident HSP70, four redox-active <scene name='User:Lydia_Lamriben/Sandbox1/Thioredoxin_domains/1'>thioredoxin</scene> domains (displayed here in green) and their respective redox-active CXXC motifs labeled in red and two <scene name='User:Lydia_Lamriben/Sandbox1/Thioredoxin-like_domains/3'>thioredoxin-like</scene> domains shown in yellow, which lack CXXC redox-active motifs. | <scene name='User:Lydia_Lamriben/Sandbox1/Erdj5/1'>ERdj5</scene> is an Endoplasmic Reticulum (ER) resident protein disulfide isomerase. It is a 793 amino acid multi-domain protein. It consists of an N-terminal <scene name='User:Lydia_Lamriben/Sandbox1/J-domain/4'>J-domain</scene> that has been shown to bind to BIP, ER resident HSP70, four redox-active <scene name='User:Lydia_Lamriben/Sandbox1/Thioredoxin_domains/1'>thioredoxin</scene> domains (displayed here in green) and their respective redox-active CXXC motifs labeled in red and two <scene name='User:Lydia_Lamriben/Sandbox1/Thioredoxin-like_domains/3'>thioredoxin-like</scene> domains shown in yellow, which lack CXXC redox-active motifs. | ||
Revision as of 00:19, 4 December 2013
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Hsp70-Hsp90 Organizing Protein (Hop)Hsp70-Hsp90 Organizing Protein (Hop)
Hop is an adaptor protein which mediates the association of the molecular chaperones Hsp70 and Hsp90 as some proteins require their coordinated activities for folding and conformational regulation. Hsp90 receives its substrates from Hsp70 in a reaction that is critically dependent on Hop, but how Hop mediates this hand-off was unclear until structural studies of Hop were conducted. Hop is not a chaperone itself, and it is composed almost entirely of Tetra-trico-peptide repeat (TPR) domains. TPR domains are defined as multiple repeats of 34 amino acids that share a degenerate consensus sequence consisting of a pattern of small and large hydrophobic amino acids, with no position being completely invariant. TPR domains are found in many proteins and often serve as interaction modules in multiprotein complexes.
TPR Domain 1 StructureTPR Domain 1 Structure
is an Endoplasmic Reticulum (ER) resident protein disulfide isomerase. It is a 793 amino acid multi-domain protein. It consists of an N-terminal that has been shown to bind to BIP, ER resident HSP70, four redox-active domains (displayed here in green) and their respective redox-active CXXC motifs labeled in red and two domains shown in yellow, which lack CXXC redox-active motifs.
FunctionFunction
ERdj5 is believed to play a critical role in ERAD (ER Associated Degradation) in that it is required for reducing ERAD substrates and facilitating their retrotranslocation from the ER to the cytoplasm. It has been shown to interact with EDEM (ER Degradation Enhancing Mannosidase), a protein that recognizes misfolded substrates and targets them for ERAD.
ReferencesReferences
1. Hagiwara M. et. al. Molecular Cell; 41. 2011
2. Ushioda R. et. al. Science; 321. 2008