The severe acu
te respira
tory syndrome (SARS) virus belongs
to
the Coronaviridea family ofviruses. I
ts virion encodes several pro
teins including a replicase and four s
truc
tural pro
teins. Here wedescribe
the
three-dimensional s
truc
ture of
the N-
terminal domain of
the SARS coronavirus (CoV)nucleocapsid pro
tein. The pro
tein consis
ts of a five-s
tranded
ta2.gif" BORDER=0 ALIGN="middle"> shee
t wi
th a folding
topology dis
tinc
tfrom o
ther RNA-binding pro
teins. Single-s
tranded RNAs bind
to
the pro
tein surface a
t the junc
tion be
tweena flexible, posi
tively charged
ta2.gif" BORDER=0 ALIGN="middle"> hairpin and
the core s
truc
ture. NMR-based screening was used
to iden
tifylow molecular weigh
t compounds
tha
t bind
to
this si
te.