Main Page

Coronavirus Spike Protein Priming

by Eric Martz
Coronavirus SARS-CoV-2 (responsible for COVID-19) has a spike protein on its surface, which enables it to infect host cells. Initially, proteases in the lungs clip the homo-trimeric spike protein at a unique sequence. This primes it, causing it to extend its receptor binding surface (shown in the above animation), optimizing binding to the host cell's ACE2 receptor (not shown). Next, spike protein initiates fusion of the virus and host cell membranes (not shown), enabling the virus RNA to enter the cell and initiate production of new virions. Knowledge of spike protein's molecular structure and function is crucial to developing effective therapies and vaccines.
>>> Visit this page >>>

Structural flexibility of the periplasmic protein, FlgA, regulates flagellar P-ring assembly in Salmonella enterica.

H Matsunami, YH Yoon, VA Meshcheryakov, K Namba, FA Samatey. Scientific Reports 2016 doi: 10.1038/srep27399
A periplasmic flagellar chaperone protein, FlgA, is required for P-ring assembly in bacterial flagella of taxa such as Salmonella enterica or Escherichia coli. Here we present the open and closed crystal structures of FlgA from Salmonella enterica serovar Typhimurium, grown under different crystallization conditions. An intramolecular disulfide cross-linked form of FlgA caused a dominant negative effect on motility of the wild-type strain.

>>> Visit this I3DC complement >>>

Polio is still here!
Polio vaccines have been available since the 1950s, but the challenges of vaccination in remote areas of Afghanistan and Pakistan have prevented worldwide eradication. In 2022, polio was found circulating in parts of New York State, USA. The polio virus has a small RNA genome enclosed in an icosahedral capsid composed of several proteins, shown cut in half. The structures of virus capsids can be explored using free FirstGlance in Jmol.

>>> Visit I3DC Interactive Visualizations >>>