The structure of the PA28–20S proteasome complex from Plasmodium falciparum and implications for proteostasis

Xie S, Metcalfe R, Hanssen E, Yang T, Gillett D, Leis A, Morton C, Kuiper M, Parker M, Spillman N, Wong W, Tsu C, Dick L, Griffin M, Tilley L, Nature Microbiology (2019) DOI

SASDES6 – The 11S subunit of the Plasmodium falciparum proteasome, PA28

Proteasome activator PA28
MWexperimental 263 kDa
MWexpected 232 kDa
VPorod 484 nm3
log I(s) 2.70×10-1 2.70×10-2 2.70×10-3 2.70×10-4
Proteasome activator PA28 small angle scattering data  s, nm-1
ln I(s)
Proteasome activator PA28 Guinier plot ln 2.70×10-1 Rg: 4.3 nm 0 (4.3 nm)-2 s2
(sRg)2I(s)/I(0)
Proteasome activator PA28 Kratky plot 1.104 0 3 sRg
p(r)
Proteasome activator PA28 pair distance distribution function Rg: 4.3 nm 0 Dmax: 12.9 nm

Data validation


Fits and models


log I(s)
 s, nm-1
Proteasome activator PA28 CORAL model

log I(s)
 s, nm-1
Proteasome activator PA28 CORAL model

log I(s)
 s, nm-1
Proteasome activator PA28 GASBOR model

Synchrotron SAXS data from solutions of the 11S subunit of the Plasmodium falciparum proteasome, PA28 in 20 mM Tris-HCl, 150 mM NaCl, 0.5 mM TCEP, 0.1% sodium azide, pH 7.4 were collected on the SAXS/WAXS beam line at the Australian Synchrotron (Melbourne, Australia) using a Pilatus 1M detector at a sample-detector distance of 2.7 m and at a wavelength of λ = 0.10332 nm (l(s) vs s, where s = 4πsinθ/λ, and 2θ is the scattering angle; s-range = 0.05 < s < 3.34 nm-1). Co-flow operations were employed (Kirby et al., 2016, Acta Cryst. D 72(12): 1254–1266) to reduce radiation damage and allow higher X-ray flux onto the sample, and an optimized chromatography system to limit sample dilution. Data were collected following fractionation using an in-line size-exclusion chromatography column (Superdex 200 5/150 (GE Healthcare), at a flow rate of 0.45 mL/min, with the column pre-equilibrated in buffer. Data were collected using a 1.5 mm sample capillary at under continuous flow at 22°C, with SAXS data frames collected every second.

Proteasome activator PA28 (PA28)
Mol. type   Protein
Organism   Plasmodium falciparum (isolate 3D7)
Olig. state   Heptamer
Mon. MW   33.2 kDa
 
UniProt   Q8I374
Sequence   FASTA
 
PDB code   6DFK
 
PDB code   6DFK