The severe acute respiratory syndrome coronavirus 3a is a novel structural protein.
The severe acute respiratory syndrome coronavirus (SARS-CoV) 3a protein is one of the opening reading frames in the viral genome with no homologue in other known coronaviruses. Expression of the 3a protein has been demonstrated during both in vitro and in vivo infection. Here we present biochemical data to show that 3a is a novel coronavirus structural protein. 3a was detected in virions purified from SARS-CoV infected Vero E6 cells although two truncated products were present predominantly instead of the full-length protein. In Vero E6 cells transiently transfected with a cDNA construct for expressing 3a, a similar cleavage was observed. Furthermore, co-expression of 3a, membrane and envelope proteins using the baculovirus system showed that both full-length and truncated 3a can be assembled into virus-like particles. This is the first report that demonstrated the incorporation of 3a into virion and showed that the SARS-CoV encodes a novel coronavirus structural protein.
Shen
Shuo
S
Institute of Molecular and Cell Biology, 61 Biopolis Drive, Proteos, Singapore 138673, Singapore.
Lin
Pi-Shiu
PS
Chao
Yu-Chan
YC
Zhang
Aihua
A
Yang
Xiaoming
X
Lim
Seng Gee
SG
Hong
Wanjin
W
Tan
Yee-Joo
YJ
D000818:Animals; D016367:Baculoviridae / Q000235:genetics; D002522:Chlorocebus aethiops; D018076:DNA, Complementary; D016366:Open Reading Frames; D010957:Plasmids; D011995:Recombination, Genetic; D014709:Vero Cells; D014759:Viral Envelope Proteins; D014764:Viral Proteins / Q000737:chemistry / Q000378:metabolism*; D015678:Viral Structural Proteins / Q000737:chemistry / Q000378:metabolism*; D000086082:Viroporin Proteins
C487105:3a protein, SARS-CoV; D018076:DNA, Complementary; D014759:Viral Envelope Proteins; D014764:Viral Proteins; D015678:Viral Structural Proteins; D000086082:Viroporin Proteins