6PXI

The crystal structure of a singly capped HslUV complex with an axial pore plug and a HslU E257Q mutation

• PDB DOI: https://doi.org/10.2210/pdb6PXI/pdb

• Classification: HYDROLASE
• Organism(s): Escherichia coli
• Expression System: Escherichia coli
• Mutation(s): Yes 


• Deposited: 2019-07-26 Released: 2020-07-29 
• Deposition Author(s): Baytshtok, V., Grant, R.A., Sauer, R.T.
• Funding Organization(s): National Institutes of Health/National Human Genome Research Institute (NIH/NHGRI)

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 3.45 Å
• R-Value Free: 0.285 
• R-Value Work: 0.257 
• R-Value Observed: 0.261 

Literature

Heat activates the AAA+ HslUV protease by melting an axial autoinhibitory plug.

Baytshtok, V., Fei, X., Shih, T.T., Grant, R.A., Santos, J.C., Baker, T.A., Sauer, R.T.

(2021) Cell Rep 34: 108639-108639

• PubMed: 33472065 
• DOI: https://doi.org/10.1016/j.celrep.2020.108639
• Primary Citation of Related Structures:  
  6PXI, 6PXK, 6PXL


• PubMed Abstract: 
  

  At low temperatures, protein degradation by the AAA+ HslUV protease is very slow. New crystal structures reveal that residues in the intermediate domain of the HslU ₆ unfoldase can plug its axial channel, blocking productive substrate binding and subsequent unfolding, translocation, and degradation by the HslV ₁₂ peptidase. Biochemical experiments with wild-type and mutant enzymes support a model in which heat-induced melting of this autoinhibitory plug activates HslUV proteolysis.

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Organizational Affiliation: 

Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.

Biological Assembly 1  

Global Symmetry: Cyclic - C6  (Explore in 3D)
Global Stoichiometry: Hetero 18-mer - A12B6 

Biological assembly 1 assigned by authors.

Biological Assembly Evidence: gel filtration

Macromolecule Content

• Total Structure Weight: 177.52 kDa 
• Atom Count: 11,163 
• Modelled Residue Count: 1,437 
• Deposited Residue Count: 1,592 
• Unique protein chains: 2

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
ATP-dependent protease subunit HslV	A, B, C, D	174	Escherichia coli	Mutation(s): 0  Gene Names: hslV EC: 3.4.25.2
UniProt
Find proteins for P0A7B8 (Escherichia coli (strain K12)) Explore P0A7B8  Go to UniProtKB:  P0A7B8

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
ATP-dependent protease ATPase subunit HslU	E, F	448	Escherichia coli	Mutation(s): 1  Gene Names: hsIU
UniProt
Find proteins for P0A6H5 (Escherichia coli (strain K12)) Explore P0A6H5  Go to UniProtKB:  P0A6H5

Small Molecules

Ligands 2 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
ADP	J [auth E], K [auth F]	ADENOSINE-5'-DIPHOSPHATE C10 H15 N5 O10 P2 XTWYTFMLZFPYCI-KQYNXXCUSA-N
SO4	G [auth A], H [auth A], I [auth C]	SULFATE ION O4 S QAOWNCQODCNURD-UHFFFAOYSA-L

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 3.45 Å
• R-Value Free: 0.285 
• R-Value Work: 0.257 
• R-Value Observed: 0.261 
• Space Group: P 3 2 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 168.604	α = 90
b = 168.604	β = 90
c = 162.886	γ = 120

Software Package:

Software Name	Purpose
HKL-2000	data scaling
PHENIX	refinement
PDB_EXTRACT	data extraction
HKL-2000	data reduction
PHASER	phasing

Structure Validation

Currently 6PXI does not have a validation slider image.

Entry History & Funding Information

Deposition Data

• Released Date: 2020-07-29 
Deposition Author(s): Baytshtok, V., Grant, R.A., Sauer, R.T.

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Funding Organization	Location	Grant Number
National Institutes of Health/National Human Genome Research Institute (NIH/NHGRI)	United States	--

Revision History  

• Version 1.0: 2020-07-29
  Type: Initial release
  
• Version 1.1: 2021-02-10
  Changes: Database references
• Version 1.2: 2023-10-11
  Changes: Data collection, Database references, Refinement description