{PDOC51926}
{PS51926; COV_E}
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* Coronavirus envelope (CoV E) protein profile *
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Coronaviruses (CoVs)  [E1] are a diverse group of enveloped, plus-stranded RNA
viruses that  infect  humans  and many animal species, in which they can cause
respiratory, enteric,   hepatic,   central  nervous  system  and  neurological
diseases of  varying severity. The main CoV structural proteins are S (spike),
E (envelope),  M  (membrane),  and  N  (nucleocapsid),  where  S, E, and M are
integral membrane  proteins. CoV E proteins are involved in several aspects of
the virus’  life  cycle,  such  as  assembly, budding, envelope formation, and
pathogenesis. They   are   ~100-residue-long   polypeptides   that  are  minor
components in virions but are abundantly expressed inside infected cells. They
are localized mainly to the endoplasmic reticulum (ER) and Golgi-complex where
they participate  in  the  assembly, budding, and intracellular trafficking of
infectious virions [1,2,3,4].

Cov E  proteins  have  a  short  hydrophilic  N-terminus,  followed by a large
hydrophobic transmembrane  (TM)  domain,  and  end with a long, hydrophilic C-
terminus, which  comprises the majority of the protein. The hydrophobic region
of the  TM domain contains at least one predicted amphipathic alpha-helix that
pentamerizes to  form an ion-conductive pore in membranes. CoV E proteins have
been proposed  to  have at least two roles. One is related to their TM channel
domain. This  would  be  active  in  the  secretory  pathway, altering lumenal
environments and  rearranging  secretory  organelles  and leading to efficient
trafficking of  virions.  The  other  would  be related to their extramembrane
domains, particularly  the  C-terminal  domain.  This  is involved in protein-
protein interactions and targeting, among other roles [1,2,3,4].

In the CoV E protein structure a longer alpha-helix encompasses the TM domain,
which is  connected  to  another  shorter C-terminal alpha-helix by a flexible
linker domain, forming an L-shape (see <PDB:2MM4>) [Li]. The CoV E pentamer is
a right  handed  alpha-helical  bundle  where the C-terminal tails coil around
each other (see <PDB:5X29>) [4].

The profile we developed covers the entire CoV E protein.

-Sequences known to belong to this class detected by the profile: ALL.
-Other sequence(s) detected in Swiss-Prot: NONE.
-Last update: June 2020 / First entry.

[ 1] Schoeman D., Fielding B.C.
     "Coronavirus envelope protein: current knowledge."
     Virol. J. 16:69-69(2019).
     PubMed=31133031; DOI=10.1186/s12985-019-1182-0
[ 2] Li Y., Surya W., Claudine S., Torres J.
     "Structure of a conserved Golgi complex-targeting signal in
     coronavirus envelope proteins."
     J. Biol. Chem. 289:12535-12549(2014).
     PubMed=24668816; DOI=10.1074/jbc.M114.560094
[ 3] Teoh K.T., Siu Y.L., Chan W.L., Schluter M.A., Liu C.J., Peiris J.S.,
     Bruzzone R., Margolis B., Nal B.
     "The SARS coronavirus E protein interacts with PALS1 and alters tight
     junction formation and epithelial morphogenesis."
     Mol. Biol. Cell. 21:3838-3852(2010).
     PubMed=20861307; DOI=10.1091/mbc.E10-04-0338
[ 4] Surya W., Li Y., Torres J.
     "Structural model of the SARS coronavirus E channel in LMPG
     micelles."
     Biochim. Biophys. Acta. Biomembr. 1860:1309-1317(2018).
     PubMed=29474890; DOI=10.1016/j.bbamem.2018.02.017
[E1] https://viralzone.expasy.org/30?outline=all_by_species

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