Spherical or helical.
60-200 nm. in diameter.
Total RNA without segmentation, positive sense.
Surface antigens are glycoproteins and nucleoproteins
Glycoproteins were characterized:
E2. Adhesion to the cell membrane.
Protein S. Form projected responsible for stimulating
neutralizing antibody and interaction with cellular receptors.
Bind to cells via specific receptors.
Enter through membrane fusion.
In the cytoplasm, the viral RNA is translated by the host
Viral proteins are synthesized, assembled, are fused to the
cell membrane and the virus out.
S – spike (receptor binding cell fusion).
E – envelope (small: envelope protein, not as abundant as S).
M – membrane protein (transmembrane budding and envelope
The cover consists of two viral glycoprotein structures S and M
S glycoprotein is richly glycosylated, high weight
molecular and is located in the outer membrane of
envelope and is responsible for the bulging projections
(peplomers) characterizing the coronaviridae, which
used as ligands in membrane fusion.
The M glycoprotein (matrix protein) is a molecule
transmembrane and is located on the inside of the cover.
Another important protein structure is the (nucleoprotein),
responsible for the helical symmetry
Nucleo capsid including the genomic RNA
A picture of
They are transmitted by aerosols secretions
It has an incubation period of 2 days to a
week, eliminating virus for one week.
The virus replicates in the cytoplasm of the cell host, mend in the
endoplasmic reticulum and pass the Golgi cisternae until they are
finally released by exocytose.
Are responsible for up to 15% of colds, taking more often in the
winter and beginning of the spring with a characteristic periodicity of
Replication of Coronavirus begins with entry to the cell which takes
place in the cytoplasm.
entry to the cell the virus particle is uncoated and the RNA genome
is deposited into the cytoplasm.
Coronavirus have single positive strand RNA genome, they can
directly produce their protein and new genome in the cytoplasm
The Coronavirus genome has a 5’ methylated cap and a
3’polyadenylated tail. This allows the RNA to attach to ribosomes for
Coronaviruses also have a protein known as a replicas that
makes negative strand that can be used as template to make
more mRNA copies.
This negative strand serves for replication of new positive
strand RNA genome
mRNA code for new viral proteins including (N,M and S).
The protein N binds genomic RNA and the protein M is
integrated into the membrane of the endoplasmic
reticular(ER), protein S after binding, assembled nucleo-
capsids with helical twisted RNA budding into the ER lumen
and are encased with membrane.
These viral progeny are finally transported by Golgi
vesicles to the cell membrane and exocytosis.
Diseases caused by coronaviruses
Coronaviruses primarily infect the upper respiratory and
gastrointestinal tract of mammals and birds. Six different currently
known strains of coronaviruses infect humans.
The most recently publicized human coronavirus, SARS-CoV which
causes SARS, has a unique pathogenesis because it causes both upper
and lower respiratory tract infections and can also cause
Coronaviruses can even cause pneumonia, either direct
viral pneumonia or a secondary bacterial pneumonia.