Functional replacement of a domain in the rubella virus p150 replicase protein by the virus capsid protein.
The rubella virus (RUBV) capsid (C) protein rescues mutants with a lethal deletion between two in-frame NotI sites in the P150 replicase gene, a deletion encompassing nucleotides 1685 to 2192 of the RUBV genome and amino acids (aa) 548 to 717 of P150 (which has a total length of 1,301 aa). The complete domain rescuable by the C protein was mapped to aa 497 to 803 of P150. Introduction of aa 1 to 277 of the C protein (lacking the C-terminal E2 signal sequence) between the NotI sites in the P150 gene in a replicon construct yielded a viable construct that synthesized viral RNA with wild-type kinetics, indicating that C and this region of P150 share a common function. Further genetic analysis revealed that an arginine-rich motif between aa 60 and 68 of the C protein was necessary for the rescue of DeltaNotI deletion mutants and substituted for an arginine-rich motif between aa 731 and 735 of the P150 protein when the C protein was introduced into P150. Possible common functions shared by these arginine-rich motifs include RNA binding and interaction with cell proteins.
Tzeng
Wen-Pin
WP
Biology Department, Georgia State University, P.O. Box 4010, Atlanta, GA 30302-4010, USA.
Frey
Teryl K
TK
D036022:Capsid Proteins / Q000235:genetics*; D016254:Mutagenesis, Insertional; D017434:Protein Structure, Tertiary; D012324:RNA-Dependent RNA Polymerase / Q000737:chemistry / Q000235:genetics*; D011995:Recombination, Genetic; D012412:Rubella virus / Q000235:genetics* / Q000502:physiology; D017384:Sequence Deletion; D014779:Virus Replication
D036022:Capsid Proteins; D012324:RNA-Dependent RNA Polymerase