5WBW

Yeast Hsp104 fragment 1-360

Summary for 5WBW

• Entry DOI: 10.2210/pdb5wbw/pdb
• Descriptor: Heat shock protein 104 (2 entities in total)
• Functional Keywords: atpase, chaperone
• Biological source: Saccharomyces cerevisiae (Baker's yeast)
• Cellular location: Cytoplasm: P31539
• Total number of polymer chains: 3
• Total formula weight: 118599.44

Authors

Lee, S. (deposition date: 2017-06-29, release date: 2018-01-03, Last modification date: 2024-03-13)

Primary citation

Lee, J.,Sung, N.,Yeo, L.,Chang, C.,Lee, S.,Tsai, F.T.F.
Structural determinants for protein unfolding and translocation by the Hsp104 protein disaggregase.
Biosci. Rep., 37:-, 2017

PubMed Abstract: The ring-forming Hsp104 ATPase cooperates with Hsp70 and Hsp40 molecular chaperones to rescue stress-damaged proteins from both amorphous and amyloid-forming aggregates. The ability to do so relies upon pore loops present in the first ATP-binding domain (AAA-1; loop-1 and loop-2 ) and in the second ATP-binding domain (AAA-2; loop-3) of Hsp104, which face the protein translocating channel and couple ATP-driven changes in pore loop conformation to substrate translocation. A hallmark of loop-1 and loop-3 is an invariable and mutational sensitive aromatic amino acid (Tyr and Tyr) involved in substrate binding. However, the role of conserved aliphatic residues (Lys, Lys, and Val) flanking the pore loop tyrosines, and the function of loop-2 in protein disaggregation has not been investigated. Here we present the crystal structure of an N-terminal fragment of Hsp104 exhibiting molecular interactions involving both AAA-1 pore loops, which resemble contacts with bound substrate. Corroborated by biochemical experiments and functional studies in yeast, we show that aliphatic residues flanking Tyr and Tyr are equally important for substrate interaction, and abolish Hsp104 function when mutated to glycine. Unexpectedly, we find that loop-2 is sensitive to aspartate substitutions that impair Hsp104 function and abolish protein disaggregation when loop-2 is replaced by four aspartate residues. Our observations suggest that Hsp104 pore loops have non-overlapping functions in protein disaggregation and together coordinate substrate binding, unfolding, and translocation through the Hsp104 hexamer.

PubMed: 29175998
DOI: 10.1042/BSR20171399

Experimental method

X-RAY DIFFRACTION (2.6 Å)