Abstract
The nucleocapsid protein VP35 of Marburgvirus, a filovirus, acts as the cofactor of the viral polymerase and plays an essential role in transcription and replication of the viral RNA. VP35 forms complexes with the genome encapsidating protein NP and with the RNA-dependent RNA polymerase L. In addition, a trimeric complex had been detected in which VP35 bridges L and the nucleoprotein NP. It has been presumed that the trimeric complex represents the active polymerase bound to the nucleocapsid. Here we present evidence that a predicted coiled-coil domain between amino acids 70 and 120 of VP35 is essential and sufficient to mediate homo-oligomerization of the protein. Substitution of leucine residues 90 and 104 abolished (i) the probability to form coiled coils, (ii) homo-oligomerization, and (iii) the function of VP35 in viral RNA synthesis. Further, it was found that homo-oligomerization-negative mutants of VP35 could not bind to L. Thus, it is presumed that homo-oligomerization-negative mutants of VP35 are unable to recruit the polymerase to the NP/RNA template. In contrast, inability to homo-oligomerize did not abolish the recruitment of VP35 into inclusion bodies, which contain nucleocapsid-like structures formed by NP. Finally, transcriptionally inactive mutants of VP35 containing the functional homo-oligomerization domain displayed a dominant-negative phenotype. Inhibition of VP35 oligomerization might therefore represent a suitable target for antiviral intervention.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.