AN N-TERMINAL DOMAIN OF THE SENDAI PARAMYXOVIRUS P-PROTEIN ACTS AS A CHAPERONE FOR THE NP PROTEIN DURING THE NASCENT CHAIN ASSEMBLY STEP OFGENOME REPLICATION
J. Curran et al., AN N-TERMINAL DOMAIN OF THE SENDAI PARAMYXOVIRUS P-PROTEIN ACTS AS A CHAPERONE FOR THE NP PROTEIN DURING THE NASCENT CHAIN ASSEMBLY STEP OFGENOME REPLICATION, Journal of virology, 69(2), 1995, pp. 849-855
Two domains involved in RNA synthesis have recently been found within
the N-terminal 77 amino acids of the Sendai virus P protein. One domai
n is required for RNA synthesis per se and has properties in common wi
th the transactivation domains of cellular transcription factors. The
second domain is thought to be specifically required for the nascent c
hain assembly step in genome replication. We have further mapped this
second domain by the construction of chimeric and deleted P proteins t
o amino acids 33 to 41 of P and by examining the abilities of these P
proteins to support DI genome replication in vivo Using glycerol gradi
ent sedimentation, we have shown that this domain is required to form
a stable complex with unassembled NP (P-NP0) and to prevent NP from as
sembling illegitimately, i.e., independently of the concurrent assembl
y of a nascent viral genome. Since the P-NP0 complex represents the fu
nctional form of unassembled NP which is delivered to the nascent chai
n during genome replication, and since amino acids 33 to 41 are not re
quired for the stable interaction of P with the assembled NP of the nu
cleocapsid, this chaperone function of P is not required for mRNA synt
hesis or the RNA synthesis step of genome replication.