PHOTO: FRANCESCO TOMASINELLI/SCIENCE SOURCE; GRAPHIC: WRAPP
ET AL
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SCIENCE sciencemag.org 13 MARCH 2020 • VOL 367 ISSUE 6483 1207CORONAVIRUS
Structure of the nCoV
trimeric spike
The World Health Organization
has declared the outbreak of a
novel coronavirus (2019-nCoV)
to be a public health emergency
of international concern. The
virus binds to host cells through
its trimeric spike glycoprotein,
making this protein a key target
for potential therapies anddiagnostics. Wrapp et al. deter-
mined a 3.5-angstrom-resolution
structure of the 2019-nCoV
trimeric spike protein by cryo–
electron microscopy. Using
biophysical assays, the authors
show that this protein binds
at least 10 times more tightly
than the corresponding spike
protein of severe acute respira-
tory syndrome (SARS)–CoV to
their common host cell receptor.
They also tested three antibodies
known to bind to the SARS-CoV
spike protein but did not detect
binding to the 2019-nCoV spike
protein. These studies provide
valuable information to guide the
development of medical counter-
measures for 2019-nCoV. —VV
Science, this issue p. 1260ORGANIC CHEMISTRY
Asymmetry
on the plus side
Numerous positively charged
metal catalysts have been pairedwith chiral negative ions to select
for just one of two mirror-image
products. Genov et al. now report
a potentially general strategy
to invert the charges in this
paradigm. Because intrinsically
negative metal catalysts are
comparatively rare, the authors
appended a sulfonate group to
the common bipyridyl ligand.
Iridium complexes of this ligand
paired with chiral positive ions
could borylate just one of two
aryl rings appended to carbon
or phosphorus centers with high
enantioselectivity. —JSY
Science, this issue p. 1246FUNCTIONAL AMYLOIDS
How amyloid can be a
substrate of memory
Formation of memories requires
changes in the molecular
composition of the synapse.
How these changes occur and
what maintains this altered
synaptic composition soRESEARCH
Edited by Michael FunkIN SCIENCE JOURNALS
GLACIAL CYCLESAn underground record of past deglaciations
U
nderstanding more exactly how the timing of deglaciations
depends on changes in insolation, or the energy received by Earth
from the Sun, requires precise and independent records of both
environmental change and solar energy input. Bajo et al. strength-
ened the weak link of that two-member chain, the environmental
record, by developing a precise, radiometrically dated chronology of
the 11 deglaciations of the past million years derived from speleothems.
This allowed them to show more clearly how the initiation and duration
of glacial terminations over that period depended on solar obliquity and
precession. —HJS
Science, this issue p. 1235Speleothems, or cave formations, in the Corchia cave system in Italy have provided
precise records of the timing of deglaciations over the past million years.The
trimeric
spike protein
of the
2019 novel
coronavirusFRUSTRATED MAGNETISM
Looking for a
crystalline 2D spin ice
Spin ices—materials in which
local magnetic spins respect
“ice rules” similar to those in
water ice—are typically three-
dimensional. Two-dimensional
(2D) ice rules can also be for-
mulated and have been found
to be satisfied in engineered
nanomagnetic systems, usually
referred to as artificial spin
ices. Zhao et al. used neutron
scattering and thermodynamic
measurements to study a crys-
talline candidate for a 2D spin
ice, the intermetallic compound
HoAgGe. They found that at
low temperatures, the local
spins on the distorted kagome
planes of this quasi-2D material
respect 2D ice rules. Increasing
the temperature led to a series
of transitions consistent with
theoretical expectations. —JS
Science, this issue p. 1218Published by AAAS