Deletion analysis defines a carboxyl-proximal region of Sendai virus P protein that binds to the polymerase L protein.
The Sendai virus RNA polymerase complex consists of two viral proteins, L and P, which must be coexpressed in order to form the active enzyme. Pulse-chase experiments show that the L protein is unstable when synthesized in the absence of the P protein, but is stable in the P-L complex. Using sequential deletions in the P protein (568 amino acids), we have mapped the site on the P protein where the L protein binds by co-immunoprecipitation and gradient sedimentation analyses. The L-binding site residues in the C-terminal half of the P protein, since deletion of up to amino acid 324 of P protein does not affect complex formation. The L-binding site was mapped to a region of P protein encompassing amino acids 412-478. This region lies between the previously mapped amino acid regions which form the nucleocapsid-binding domain (amino acids 345-411 and 479-568). The data suggest that the L and NP protein-binding domains on P protein do not overlap.
Smallwood
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Department of Immunology and Medical Microbiology, College of Medicine, University of Florida, Gainesville 32610-0266.
Ryan
K W
KW
Moyer
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SA
D000818:Animals; D001665:Binding Sites; D002460:Cell Line; D002499:Centrifugation, Density Gradient; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D004789:Enzyme Activation; D006801:Humans; D010750:Phosphoproteins / Q000378:metabolism*; D011233:Precipitin Tests; D011485:Protein Binding; D017384:Sequence Deletion; D014709:Vero Cells; D014764:Viral Proteins / Q000378:metabolism*
C055859:P protein, Sendai virus; D010750:Phosphoproteins; D014764:Viral Proteins; C064365:L protein, Sendai virus; D012321:DNA-Directed RNA Polymerases