Nair, Smita and Savithri, HS (2008) Characterization of P8, a non-structural protein of Sesbania mosaic virus. In: Indian Journal Of Virology, 19 (1). p. 106.Full text not available from this repository. (Request a copy)
Sesbania mosaic virus (SeMV) is a positive sense RNA virus. The genome has two overlapping ORFs (ORF 2a and ORF 2b) that are translated to give polyproteins 2a and 2ab. The polyprotein 2ab is synthesized by ribosomal frameshifting mechanism. Both the polyproteins are processed by the N-terminal serine protease domain at specific E-T/S sites. Polyprotein 2a was shown to have a domain arrangement of Protease-VPg-P10-P8 as confirmed by mutational analysis of the specific cleavage sites. The C-terminal domain of size 8 kDa (P8) released after cleavage, moved as 14 kDa on the SDS-PAGE. In order to investigate the function of P8 and the reason for the abnormal behaviour, P8 was cloned and expressed in BL21 (DE3) pLys S cells. The recombinant protein also moved abnormally on the SDS-PAGE. The fusion proteins of P8 with other proteins also showed the same abnormality, suggesting that it was due to the inherent nature of P8 and not because of any oligomerization or covalent linkage to any protein. The secondary structure predictions and CD spectral analysis suggests that P8 is natively unfolded because of high net charge (pI-11.75). Sequence analysis of P8 showed the presence of nucleic acid binding sites and a Nuclear Localization Signal. The purified P8 was shown to bind to both genomic RNA and dsDNA by EMSA. Further studies are in progress to elucidate the function of P8.
|Item Type:||Journal Article|
|Additional Information:||Copyright of this artilce belongs to Indian Virological Society.|
|Department/Centre:||Division of Biological Sciences > Biochemistry|
|Date Deposited:||14 Jul 2009 13:27|
|Last Modified:||14 Jul 2009 13:27|
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