6M7M

rac-GSTSTA from degenerate octameric repeats in InaZ, residues 707-712

Summary for 6M7M

• Entry DOI: 10.2210/pdb6m7m/pdb
• Related: 6EEX
• Descriptor: L-GSTSTA from ice nucleation protein, inaZ, and its enantiomer, D-GSTSTA (2 entities in total)
• Functional Keywords: amyloid, racemic, ice nucleation, microed, inaz, pseudomonas syringae, protein fibril
• Biological source: Pseudomonas syringae
• Total number of polymer chains: 1
• Total formula weight: 522.51

Authors

Zee, C.,Glynn, C.,Gallagher-Jones, M.,Miao, J.,Santiago, C.G.,Cascio, D.,Gonen, T.,Sawaya, M.R.,Rodriguez, J.A. (deposition date: 2018-08-20, release date: 2019-04-03, Last modification date: 2024-03-13)

Primary citation

Zee, C.T.,Glynn, C.,Gallagher-Jones, M.,Miao, J.,Santiago, C.G.,Cascio, D.,Gonen, T.,Sawaya, M.R.,Rodriguez, J.A.
Homochiral and racemic MicroED structures of a peptide repeat from the ice-nucleation protein InaZ.
IUCrJ, 6:197-205, 2019

PubMed Abstract: The ice-nucleation protein InaZ from contains a large number of degenerate repeats that span more than a quarter of its sequence and include the segment GSTSTA. structures of this repeat segment, resolved to 1.1 Å by microfocus X-ray crystallography and to 0.9 Å by the cryo-EM method MicroED, were determined from both racemic and homochiral crystals. The benefits of racemic protein crystals for structure determination by MicroED were evaluated and it was confirmed that the phase restriction introduced by crystal centrosymmetry increases the number of successful trials during the phasing of the electron diffraction data. Both homochiral and racemic GSTSTA form amyloid-like protofibrils with labile, corrugated antiparallel β-sheets that mate face to back. The racemic GSTSTA protofibril represents a new class of amyloid assembly in which all-left-handed sheets mate with their all-right-handed counterparts. This determination of racemic amyloid assemblies by MicroED reveals complex amyloid architectures and illustrates the racemic advantage in macromolecular crystallography, now with submicrometre-sized crystals.

PubMed: 30867917
DOI: 10.1107/S2052252518017621

Experimental method

X-RAY DIFFRACTION (1.101 Å)