ايران NR34 پروتيين ويروس بيماري نيوكاسل از ايزوله F ژن HR2 و HR1 كلونينگ و تعيين توالي قطعات

Cloning and Determination of HR1 and HR2 Sequences of F Protein of Newcastle Disease Virus of NR43 Isolates of Iran

Purpose: Newcastle disease virus (NDV) is a paramyxovirus, which causes Newcastle disease. This disease brings about great economical losses in poultry industry. Fusion protein, which is an essential factor in paramyxovirus pathogenicity, consists of HR1, HR2 and a fusion peptide that plays an important role in the fusion mechanism of the virus. Mutation in these regions and the produced peptides can block virus fusion. In this study, we selected one of the native isolates of Newcastle disease virus (i.e. NR43) to study its genomic sequence as a paramyxovirus model with emphasizing on the important regions. Materials & Methods: After RNA extraction, two regions of genomic RNA with about 800 bp (A: 10-820 and B: 810-1636) were amplified by RT-PCR and the products were cloned into a T-vector, then the inserts were sequenced. Results and Discussion: Alignment of sequence A with other strains of Newcastle virus by using Blast software (www.ncbi.nlm.nih.gov/blast), showed maximum similarity, first to Russian strain Vol 95 (Y16169) and then to Chinese viruses. Cleavage site sequence (RRQRR) indicates that the virus is also Velogenic. Comparison of HR1 sequence of NR43 with other strains of NDV, showed a novel mutation amino acid number 82 (F instead of L). The study of B sequence, containing HR2 domain, showed highly conserved regions with other NDV HR2 domain.