1356 10 DECEMBER 2021¥VOL 374 ISSUE 6573 science.orgSCIENCE
Delta (B.1.617.2)
one RBD-up conformation 2
S2
FPPR
NTD
RBD
CTD1
630 loop CTD2
C
Kappa (B.1.617.1)
closed conformation
S2
FPPR
NTD
RBD
CTD1
630 loop CTD2
D Kappa (B.1.617.1)
one RBD-up conformation 1
S2
FPPR
NTD
RBD
CTD1
630 loop CTD2
E
Delta (B.1.617.2)
closed conformation
S2
FPPR
NTD RBD
CTD1
630 loop
A
F157del
R158del
L452R
E156G
D950N
T19R
G142D
D614G
T478K L452R
T478K
P681R
Delta (B.1.617.2)
one RBD-up conformation 1
S2
FPPR
NTD
RBD
CTD1
CTD2
CTD2
630 loop
B
Kappa (B.1.617.1)
one RBD-up conformation 2
F
Delta (B.1.617.2)
closed conformation
I
630 loop FPPR
RBD down
RBD down
RBD down
a
bc
a
c
a
c
b b
617
644
823
862
617
644 823
862
617
823 644
862
Gamma (B.1.1.28)
one RBD-up conformation 1
G
S2
FPPR
NTD RBD
CTD1
630 loop
N501Y E484K
K417T
D138Y
P26S D614G
T20N
L18F
CTD2
S2
FPPR
NTD
RBD
CTD1
CTD2
630 loop
Gamma (B.1.1.28)
one RBD-up conformation 2
H
S2
FPPR
NTD
RBD
CTD1
630 loop CTD2
E154K
Q218H
L452R
E484Q
D614G
H1101D
V1264L
P681R
L452R
E484Q
R190S
H655Y
V1176F
T1027I
Fig. 3. Cryo-EM structures of full-length SARS-CoV-2 S proteins from the
Delta, Kappa, and Gamma variants.(AtoC) The structures of the closed
prefusion conformation and two one-RBD-up conformations of the Delta S trimer
are shown in the ribbon diagrams, with one protomer colored as follows: NTD in
blue, RBD in cyan, CTD1 in green, CTD2 in light green, S2 in light blue, the
630 loop in red, and the FPPR in magenta. (DtoF) The structures of the closed
prefusion conformation and two one-RBD-up conformation of the Kappa S
trimer are shown in the ribbon diagrams, with the same color scheme as in (A).
(G) and (H) The structures of the two one-RBD-up conformations of the Gamma
S trimer are shown in the ribbon diagrams with the same color scheme as in
(A). All mutations in the three variants, as compared to the original virus (D614),
are highlighted in the sphere model. (I) Structures in the Delta closed trimer
of segments (residues 617 to 644) containing the 630 loop (red) and segments
(residues 823 to 862) containing the FPPR (magenta) from each of the
three protomers (A), (B), and (C). The position of each RBD is indicated.
Dashed lines indicate gaps in the chain trace (disordered loops).
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