6u9b

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Hsp90a NTD covalently bound to sulfonyl fluoride 5 at K58Hsp90a NTD covalently bound to sulfonyl fluoride 5 at K58

Structural highlights

6u9b is a 1 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 1.75Å
Ligands:
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

HS90A_HUMAN Molecular chaperone that promotes the maturation, structural maintenance and proper regulation of specific target proteins involved for instance in cell cycle control and signal transduction. Undergoes a functional cycle that is linked to its ATPase activity. This cycle probably induces conformational changes in the client proteins, thereby causing their activation. Interacts dynamically with various co-chaperones that modulate its substrate recognition, ATPase cycle and chaperone function.[1] [2]

Publication Abstract from PubMed

Targeted covalent modification of surface-exposed lysines is challenging due to their low intrinsic reactivity and high prevalence throughout the proteome. Strategies for optimizing the rate of covalent bond formation by a reversibly bound inhibitor (kinact) typically involve increasing the reactivity of the electrophile, which increases the risk of off-target modification. Here, we employ an alternative approach for increasing kinact of a lysine-targeted covalent Hsp90 inhibitor, independent of the reversible binding affinity (Ki) or the intrinsic electrophilicity. Starting with a noncovalent ligand, we appended a chiral, conformationally constrained linker, which orients an arylsulfonyl fluoride to react rapidly and enantioselectively with Lys58 on the surface of Hsp90. Biochemical experiments and high-resolution crystal structures of covalent and noncovalent ligand/Hsp90 complexes provide mechanistic insights into the role of ligand conformation in the observed enantioselectivity. Finally, we demonstrate selective covalent targeting of cellular Hsp90, which results in a prolonged heat shock response despite concomitant degradation of the covalent ligand/Hsp90 complex. Our work highlights the potential of engineering ligand conformational constraints to dramatically accelerate covalent modification of a distal, poorly nucleophilic lysine on the surface of a protein target.

Ligand Conformational Bias Drives Enantioselective Modification of a Surface-Exposed Lysine on Hsp90.,Cuesta A, Wan X, Burlingame AL, Taunton J J Am Chem Soc. 2020 Feb 3. doi: 10.1021/jacs.9b09684. PMID:32009391[3]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

See Also

References

  1. Martinez-Ruiz A, Villanueva L, Gonzalez de Orduna C, Lopez-Ferrer D, Higueras MA, Tarin C, Rodriguez-Crespo I, Vazquez J, Lamas S. S-nitrosylation of Hsp90 promotes the inhibition of its ATPase and endothelial nitric oxide synthase regulatory activities. Proc Natl Acad Sci U S A. 2005 Jun 14;102(24):8525-30. Epub 2005 Jun 3. PMID:15937123 doi:10.1073/pnas.0407294102
  2. Forsythe HL, Jarvis JL, Turner JW, Elmore LW, Holt SE. Stable association of hsp90 and p23, but Not hsp70, with active human telomerase. J Biol Chem. 2001 May 11;276(19):15571-4. Epub 2001 Mar 23. PMID:11274138 doi:10.1074/jbc.C100055200
  3. Cuesta A, Wan X, Burlingame AL, Taunton J. Ligand Conformational Bias Drives Enantioselective Modification of a Surface-Exposed Lysine on Hsp90. J Am Chem Soc. 2020 Feb 3. doi: 10.1021/jacs.9b09684. PMID:32009391 doi:http://dx.doi.org/10.1021/jacs.9b09684

6u9b, resolution 1.75Å

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