Title: Homochiral and racemic MicroED structures of a peptide repeat from the ice-nucleation protein InaZ

Abstract

The ice-nucleation protein InaZ from Pseudomonas syringae contains a large number of degenerate repeats that span more than a quarter of its sequence and include the segment GSTSTA.Ab initio 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 ab initio 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.

Authors:

Zee, Chih-Te; Glynn, Calina ;

• Search DOE PAGES for author "Glynn, Calina"
• Search DOE PAGES for ORCID "0000-0002-2197-2357"

Gallagher-Jones, Marcus ;

• Search DOE PAGES for author "Gallagher-Jones, Marcus"
• Search DOE PAGES for ORCID "0000-0003-4227-917X"

Miao, Jennifer ;

• Search DOE PAGES for author "Miao, Jennifer"
• Search DOE PAGES for ORCID "0000-0001-5527-295X"

Santiago, Carlos G. ;

• Search DOE PAGES for author "Santiago, Carlos G."
• Search DOE PAGES for ORCID "0000-0001-9675-5931"

Cascio, Duilio; Gonen, Tamir ;

• Search DOE PAGES for author "Gonen, Tamir"
• Search DOE PAGES for ORCID "0000-0003-3326-1242"

Sawaya, Michael R. ;

• Search DOE PAGES for author "Sawaya, Michael R."
• Search DOE PAGES for ORCID "0000-0003-0874-9043"

Rodriguez, Jose A.

• Search DOE PAGES for author "Rodriguez, Jose A."
• Search DOE PAGES for ORCID "0000-0002-0248-4964"

Publication Date:

Thu Jan 24 00:00:00 EST 2019

Research Org.:

Argonne National Laboratory (ANL), Argonne, IL (United States). Advanced Photon Source (APS)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES); Howard Hughes Medical Institute; National Institutes of Health (NIH); National Institute of General Medical Sciences (NIGMS); National Science Foundation (NSF); Arnold and Mabel Beckman Foundation; Searle Scholars Program; Pew Charitable Trusts; QCB Collaboratory

OSTI Identifier:

1617919

Alternate Identifier(s):

OSTI ID: 1502238

Grant/Contract Number:  

FC02-02ER63421; P41 GM103403; DMR 1548924; GM007185

Resource Type:

Published Article

Journal Name:

IUCrJ

Additional Journal Information:

Journal Name: IUCrJ Journal Volume: 6 Journal Issue: 2; Journal ID: ISSN 2052-2525

Publisher:

International Union of Crystallography

Country of Publication:

United Kingdom

Language:

English

Subject:

59 BASIC BIOLOGICAL SCIENCES; amyloid; racemic; electron diffraction; ice nucleation; intermolecular interactions; co-crystals; electron crystallography; structural biology