Structural plasticity of NFU1 upon interaction with binding partners: insights into the mitochondrial [4Fe-4S] cluster pathway

Da Vela S, Saudino G, Lucarelli F, Banci L, Svergun D, Ciofi-Baffoni S, Journal of Molecular Biology :168154 (2023) DOI

SASDPD8 – Human apo iron-sulfur cluster assembly 1/iron-sulfur cluster assembly 2/NFU1 iron-sulfur cluster scaffold protein complex (ISCA1-ISCA2-NFU1)

Iron-sulfur cluster assembly 1 homolog, mitochondrial
NFU1 iron-sulfur cluster scaffold homolog, mitochondrial (F118S, E168G)
Iron-sulfur cluster assembly 2 homolog, mitochondrial
MWexperimental 47 kDa
MWexpected 49 kDa
VPorod 70 nm3
log I(s) 4.88×103 4.88×102 4.88×101 4.88×100
Iron-sulfur cluster assembly 1 homolog, mitochondrial NFU1 iron-sulfur cluster scaffold homolog, mitochondrial (F118S, E168G) Iron-sulfur cluster assembly 2 homolog, mitochondrial small angle scattering data  s, nm-1
ln I(s)
Iron-sulfur cluster assembly 1 homolog, mitochondrial NFU1 iron-sulfur cluster scaffold homolog, mitochondrial (F118S, E168G) Iron-sulfur cluster assembly 2 homolog, mitochondrial Guinier plot ln 4.88×103 Rg: 3.2 nm 0 (3.2 nm)-2 s2
(sRg)2I(s)/I(0)
Iron-sulfur cluster assembly 1 homolog, mitochondrial NFU1 iron-sulfur cluster scaffold homolog, mitochondrial (F118S, E168G) Iron-sulfur cluster assembly 2 homolog, mitochondrial Kratky plot 1.104 0 3 sRg
p(r)
Iron-sulfur cluster assembly 1 homolog, mitochondrial NFU1 iron-sulfur cluster scaffold homolog, mitochondrial (F118S, E168G) Iron-sulfur cluster assembly 2 homolog, mitochondrial pair distance distribution function Rg: 3.3 nm 0 Dmax: 11.7 nm

Data validation


Fits and models


log I(s)
 s, nm-1
Iron-sulfur cluster assembly 1 homolog, mitochondrial NFU1 iron-sulfur cluster scaffold homolog, mitochondrial (F118S, E168G) Iron-sulfur cluster assembly 2 homolog, mitochondrial CORAL model

log I(s)
 s, nm-1
Iron-sulfur cluster assembly 1 homolog, mitochondrial NFU1 iron-sulfur cluster scaffold homolog, mitochondrial (F118S, E168G) Iron-sulfur cluster assembly 2 homolog, mitochondrial DAMMIF model

Synchrotron SAXS data from solutions of the ISCA1-ISCA2-NFU1 complex in 50 mM phosphate, 150 mM NaCl, 5 mM DTT, pH 7 were collected on the EMBL P12 beam line at PETRA III (DESY, Hamburg, Germany) using a Pilatus 6M detector at a sample-detector distance of 3.1 m and at a wavelength of λ = 0.124 nm (I(s) vs s, where s = 4πsinθ/λ, and 2θ is the scattering angle). In-line size-exclusion chromatography (SEC) SAS was employed. The SEC parameters were as follows: A 30.00 μl sample at 20.4 mg/ml was injected at a 0.30 ml/min flow rate onto a GE Superdex 75 Increase 5/150 column at 20°C. 900 successive 0.995 second frames were collected. The data were normalized to the intensity of the transmitted beam and radially averaged; the scattering of the solvent-blank was subtracted.

Iron-sulfur cluster assembly 1 homolog, mitochondrial (ISCA1)
Mol. type   Protein
Organism   Homo sapiens
Olig. state   Monomer
Mon. MW   14.2 kDa
 
UniProt   Q9BUE6 (1-129)
Sequence   FASTA
 
NFU1 iron-sulfur cluster scaffold homolog, mitochondrial (F118S, E168G) (apo NFU1)
Mol. type   Protein
Organism   Homo sapiens
Olig. state   Monomer
Mon. MW   22.1 kDa
 
UniProt   Q9UMS0 (59-254)
Sequence   FASTA
 
Iron-sulfur cluster assembly 2 homolog, mitochondrial (Human ISCA2)
Mol. type   Protein
Organism   Homo sapiens
Olig. state   Monomer
Mon. MW   12.6 kDa
 
UniProt   Q86U28 (44-154)
Sequence   FASTA