title: A coiled-coil motif in non-structural protein 3 (NS3) of bluetongue virus forms an oligomer.
abstract: Bluetongue, an arthropod-borne non-contagious hemorrhagic disease of small ruminants, is caused by bluetongue virus (BTV). Several structural and non-structural proteins encoded by BTV have been associated with virulence mechanisms. In the present study, the NS3 protein sequences of bluetongue viral serotypes were analyzed for the presence of heptad regions and oligomer formation. Bioinformatic analysis of NS3 sequences of all 26 BTV serotypes revealed the presence of at least three coiled-coil motifs (CCMs). A conserved α-helical heptad sequence was identified at 14-26 aa (CCM-I), 185-198aa (CCM-II), and 94-116 aa (CCM-III). Among these, CCM-I occurs close to the N-terminus of NS3 and was presumed to be involved in oligomerization. Furthermore, the N-terminus of NS3 (1M-R117 aa) was over-expressed as a recombinant fusion protein in a prokaryotic expression system. Biochemical characterization of recombinant NS3Nt protein revealed that it forms SDS-resistant dimers and high-order oligomers (hexamer and/or octamer) under reducing or non-reducing conditions. Coiled-coil motifs are believed to be critical for NS protein oligomerization and have potential roles in the formation of viroporin ring/pore either with six/eight subunits and this is the first study toward characterization of CCMs in NS3 of bluetongue virus.
authors: Division of Virology, ICAR-Indian Veterinary Research Institute (IVRI), Regional Campus, Mukteswar, Nainital District, Uttarakhand (UK), 263138, India.
authors: Nirmal
authors: N
authors: Chacko
authors: Division of Virology, ICAR-Indian Veterinary Research Institute (IVRI), Regional Campus, Mukteswar, Nainital District, Uttarakhand (UK), 263138, India.
authors: Nihar Nalini
authors: NN
authors: Mohanty
authors: Division of Virology, ICAR-Indian Veterinary Research Institute (IVRI), Regional Campus, Mukteswar, Nainital District, Uttarakhand (UK), 263138, India.
authors: Sanchay Kumar
authors: SK
authors: Biswas
authors: Division of Virology, ICAR-Indian Veterinary Research Institute (IVRI), Regional Campus, Mukteswar, Nainital District, Uttarakhand (UK), 263138, India.
authors: Karam
authors: K
authors: Chand
authors: Division of Virology, ICAR-Indian Veterinary Research Institute (IVRI), Regional Campus, Mukteswar, Nainital District, Uttarakhand (UK), 263138, India.|ICAR-National Institute of Veterinary Epidemiology and Disease Informatics, (NIVEDI), Bangalore, Karnataka, 560064, India.
authors: Revanaiah
authors: R
authors: Yogisharadhya
authors: Division of Virology, ICAR-Indian Veterinary Research Institute (IVRI), Regional Campus, Mukteswar, Nainital District, Uttarakhand (UK), 263138, India.
authors: Awadh Bihari
authors: AB
authors: Pandey
authors: ICAR-Indian Veterinary Research Institute (IVRI), Eastern Regional Station, Kolkata, West Bengal (WB), 700037, India.
authors: Bimalendu
authors: B
authors: Mondal
authors: Division of Virology, ICAR-Indian Veterinary Research Institute (IVRI), Regional Campus, Mukteswar, Nainital District, Uttarakhand (UK), 263138, India. sbshivachandra@gmail.com.|ICAR-National Institute of Veterinary Epidemiology and Disease Informatics, (NIVEDI), Bangalore, Karnataka, 560064, India. sbshivachandra@gmail.com.
authors: Sathish Bhadravati
authors: SB
authors: Shivachandra
mesh_terms: D001820:Bluetongue virus / Q000502:physiology*; D019295:Computational Biology; D004591:Electrophoresis, Polyacrylamide Gel; D011485:Protein Binding; D011487:Protein Conformation; D054730:Protein Interaction Domains and Motifs; D055503:Protein Multimerization; D017422:Sequence Analysis, DNA; D017361:Viral Nonstructural Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*
chemical_list: C075080:S10 protein, Bluetongue virus; D017361:Viral Nonstructural Proteins
keywords: Bluetongue virus; Coiled-coil motif; Heptad; Non-structural protein 3; Oligomer; Recombinant fusion protein