PDBsum entry 4nip

Protein fibril

PDB id: 4nip

Contents

Ligands

GLY-VAL-ILE-GLY-ILE-ALA-GLN

Waters ×3

PDB id:

4nip

Name:

Protein fibril

Title:

Gvigiaq segment 147-153 from human superoxide dismutase

Structure:

Gvtgiaq segment from superoxide dismutase [cu-zn]. Chain: a. Fragment: unp residues 148-154. Synonym: superoxide dismutase 1, hsod1. Engineered: yes

Source:

Synthetic: yes. Homo sapiens. Human. Organism_taxid: 9606

Resolution:

1.90Å R-factor: 0.234 R-free: 0.249

Authors:

S.A.Sievers,M.R.Sawaya,D.Eisenberg,M.I.Ivanova

Key ref:

M.I.Ivanova et al. (2014). Aggregation-triggering segments of SOD1 fibril formation support a common pathway for familial and sporadic ALS. Proc Natl Acad Sci U S A, 111, 197-201. PubMed id: 24344300 DOI: 10.1073/pnas.1320786110

Date:

06-Nov-13 Release date: 04-Dec-13

DOI no: 10.1073/pnas.1320786110

Proc Natl Acad Sci U S A 111:197-201 (2014)

PubMed id: 24344300

Aggregation-triggering segments of SOD1 fibril formation support a common pathway for familial and sporadic ALS.

M.I.Ivanova, S.A.Sievers, E.L.Guenther, L.M.Johnson, D.D.Winkler, A.Galaleldeen, M.R.Sawaya, P.J.Hart, D.S.Eisenberg.

ABSTRACT

ALS is a terminal disease of motor neurons that is characterized by accumulation of proteinaceous deposits in affected cells. Pathological deposition of mutated Cu/Zn superoxide dismutase (SOD1) accounts for ∼20% of the familial ALS (fALS) cases. However, understanding the molecular link between mutation and disease has been difficult, given that more than 140 different SOD1 mutants have been observed in fALS patients. In addition, the molecular origin of sporadic ALS (sALS) is unclear. By dissecting the amino acid sequence of SOD1, we identified four short segments with a high propensity for amyloid fibril formation. We find that fALS mutations in these segments do not reduce their propensity to form fibrils. The atomic structures of two fibril-forming segments from the C terminus, (101)DSVISLS(107) and (147)GVIGIAQ(153), reveal tightly packed β-sheets with steric zipper interfaces characteristic of the amyloid state. Based on these structures, we conclude that both C-terminal segments are likely to form aggregates if available for interaction. Proline substitutions in (101)DSVISLS(107) and (147)GVIGIAQ(153) impaired nucleation and fibril growth of full-length protein, confirming that these segments participate in aggregate formation. Our hypothesis is that improper protein maturation and incompletely folded states that render these aggregation-prone segments available for interaction offer a common molecular pathway for sALS and fALS.