In
molecular biology
Molecular biology is the branch of biology that seeks to understand the molecular basis of biological activity in and between cells, including biomolecular synthesis, modification, mechanisms, and interactions. The study of chemical and physi ...
, holdases are a particular kind of
molecular chaperones
In molecular biology, molecular chaperones are proteins that assist the conformational folding or unfolding of large proteins or macromolecular protein complexes. There are a number of classes of molecular chaperones, all of which function to ass ...
that assist the non-covalent folding of proteins in an ATP-independent manner. Examples of holdases are
DnaJ
In molecular biology, chaperone DnaJ, also known as Hsp40 (heat shock protein 40 kD), is a molecular chaperone protein. It is expressed in a wide variety of organisms from bacteria to humans.
Function
Molecular chaperones are a diverse family ...
and
Hsp33.
Holdases bind to protein folding intermediates to prevent their aggregation but without directly refolding them. They stand in opposition to
foldases, which are chaperones that use ATP to fold proteins.
See also
*
Foldase
*
Chaperonin
*
Co-chaperone
Co-chaperones are proteins that assist chaperones in protein folding and other functions. Co-chaperones are the non-client binding molecules that assist in protein folding mediated by Hsp70 and Hsp90. They are particularly essential in stimulation ...
References
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Molecular chaperones
Protein biosynthesis