SARS-related coronavirus S-protein structures reveal synergistic RBM interactions underpinning high-affinity human ACE2 binding.

High-affinity and specific binding toward the human angiotensin-converting enzyme 2 (hACE2) receptor by severe acute respiratory syndrome coronavirus (SARS)-related coronaviruses (SARSr-CoVs) remains incompletely understood. We report cryo-electron microscopy structures of eight different S-proteins from SARSr-CoVs found across Asia, Europe, and Africa. These S-proteins all adopt tightly packed, locked, prefusion conformations.

Structure of a unique PSII-Pcb tetrameric megacomplex in a chlorophyll -containing cyanobacterium.

is a unique cyanobacterium using chlorophyll (Chl ) as its major pigment and thus can use far-red light for photosynthesis. Photosystem II (PSII) of associates with a number of prochlorophyte Chl-binding (Pcb) proteins to act as the light-harvesting system. We report here the cryo-electron microscopic structure of a PSII-Pcb megacomplex from at a 3.

Disulfide stabilization reveals conserved dynamic features between SARS-CoV-1 and SARS-CoV-2 spikes.

SARS-CoV-2 spike protein (S) is structurally dynamic and has been observed by cryo-EM to adopt a variety of prefusion conformations that can be categorized as locked, closed, and open. S-trimers adopting locked conformations are tightly packed featuring structural elements incompatible with RBD in the "up" position. For SARS-CoV-2 S, it has been shown that the locked conformations are transient under neutral pH.

Omicron SARS-CoV-2 mutations stabilize spike up-RBD conformation and lead to a non-RBM-binding monoclonal antibody escape.

Omicron SARS-CoV-2 is rapidly spreading worldwide. To delineate the impact of emerging mutations on spike's properties, we performed systematic structural analyses on apo Omicron spike and its complexes with human ACE2 or S309 neutralizing antibody (NAb) by cryo-EM. The Omicron spike preferentially adopts the one-RBD-up conformation both before and after ACE2 binding, which is in sharp contrast to the orchestrated conformational changes to create more up-RBDs upon ACE2 binding as observed in the prototype and other four variants of concern (VOCs).

Structure of infective Getah virus at 2.8 Å resolution determined by cryo-electron microscopy.

Getah virus (GETV), a member of the genus alphavirus, is a mosquito-borne pathogen that can cause pyrexia and reproductive losses in animals. Although antibodies to GETV have been found in over 10% of healthy people, there are no reports of clinical symptoms associated with GETV. The biological and pathological properties of GETV are largely unknown and antiviral or vaccine treatments against GETV are still unavailable due to a lack of knowledge of the structure of the GETV virion.

Receptor binding and complex structures of human ACE2 to spike RBD from omicron and delta SARS-CoV-2.

The coronavirus disease 2019 (COVID-19) pandemic continues worldwide with many variants arising, some of which are variants of concern (VOCs). A recent VOC, omicron (B.1.