Coronavirus envelope protein (E protein)

The **coronavirus envelope protein (E protein)** is a small integral membrane protein present in coronaviruses, including SARS-CoV-2, SARS-CoV, and MERS-CoV[1][2][6]. It is typically less than 110 amino acids in length (75 residues in SARS-CoV-2) and is one of the four main structural proteins of the virion, alongside spike (S), membrane (M), and nucleocapsid (N) proteins[1]. The E protein consists of a short hydrophilic N-terminal domain, a hydrophobic transmembrane domain (TMD), and a C-terminal domain that often contains a PDZ-binding motif interacting with host cell proteins[2]. It forms pentameric complexes in viral and host membranes, creating a cation-selective ion channel (viroporin) critical for viral assembly, morphogenesis, and budding[1][3][5][7][8]. Absence or inhibition of E protein impairs virion assembly and drastically reduces viral replication, although not all coronaviruses absolutely require E for replication[1][7]. The E protein also impacts pathogenesis via its effects on ion homeostasis and pro-inflammatory responses[5][7]. Hexamethylene amiloride (HMA) is a small-molecule inhibitor known to block the E protein channel activity[3][8]. Owing to its pivotal roles in coronavirus biology and infectivity, the E protein is considered a potential antiviral drug target[3][7][8].

Other names

Envelope protein EE proteinSARS-CoV-2 E proteinCoronavirus E proteinViroporin E

Ion channel inhibition (viroporin inhibition). Blockade of cation conductance.