Please use this identifier to cite or link to this item:
|標題:||The sequence and phylogenetic analysis of avian reovirus genome segments M1, M2, and M3 encoding the minor core protein mu A, the major outer capsid protein mu B, and the nonstructural protein mu NS||作者:||Su, Y.P.
|關鍵字:||avian reovirus;genome segments M1, M2, and M3;proteins mu A, mu B, and;mu NS;phylogenetic analysis;genome segment s3;sigma-ns;escherichia-coli;gene;rna;cloning;expression;evolution;s1133;s1||Project:||Journal of Virological Methods||期刊/報告no：:||Journal of Virological Methods, Volume 133, Issue 2, Page(s) 146-157.||摘要:||
The sequences and phylogenetic analyses of the M-class genome segments of 12 avian reovirus strains are described. The S 1133 M I genome segment is 2283 base pairs long, encoding a protein mu A consisted of 732 amino acids. Each M2 or M3 genome segment of 12 avian reovirus strains is 2158 or 1996 base pairs long, respectively, encoding a protein mu B or mu NS consisted of 676 and 635 amino acids, respectively. The S 1133 genome segment has the 5' GCUUUU terminal motif, but each M2 and M3 genome segment displays the 5' GCUUUUU terminal motif which is common to other known avian reovirus genome segments. The UCAUC 3'-terminal sequences of the M-class genome segments are shared by both avian and mammalian reoviruses. Noncoding regions of both 5'- and 3'-termini of the S 1133 M 1 genome segment consist of 12 and 72 nucleotides, respectively, those of each M2 genome segment consist of 29 and 98 nucleotides, respectively, and those of each M3 genome segment are 24 and 64 nucleotides, respectively. Analysis of the average degree of the M-class gene and the deduced mu-class protein sequence identities indicated that the M2 genes and the mu B proteins have the greatest level of sequence divergence. Computer searches revealed that the mu A possesses a sequence motif (NH2-Leu-Ala-Leu-Asp-Pro-Pro-Phe-COOH) (residues 458-464) indicative of N-6 adenine-specific DNA methylase. Examination of the mu B amino acid sequences indicated that the cleavage site of mu B into mu BN and mu BC is between positions 42 and 43 near the N-terminus of the protein, and this site is conserved for each protein. During in vitro treatment of virions with trypsin to yield infectious subviral particles, both the N-terminal fragment delta and the C-terminal fragment phi were shown to be generated. The site of trypsin cleavage was identified in the deduced amino acid sequence of mu B by determining the amino-terminal sequences of phi proteins: between arginine 582 and glycine 583. The predicted length of delta generated from mu BC is very similar to that of delta generated from mammalian reovirus mu 1 C. Taken together, protein mu B is structurally, and probably functionally, similar to its mammalian homolog, mu 1. In addition, two regions near the C-terminal and with a propensity to form alpha-helical coiled-coil structures as previously indicated are observed for each protein mu B. Phylogenetic analysis of the M-class genes revealed that the predicted phylograms delineated 3 M 1, 5 M2, and 2 M3 lineages, no correlation with serotype or pathotype of the viruses. The results also showed that M2 lineages I-V consist of a mixture of viruses from the M 1 and M3 genes of lineages I-III, reflecting frequent reassortment of these genes among virus strains. (c) 2005 Elsevier B.V. All rights reserved.
|Appears in Collections:||分子生物學研究所|
Show full item record
TAIR Related Article
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.