The nucleotide sequence and genome organization of the RNA-1 segment in two bromoviruses: broad bean mottle virus and cowpea chlorotic mottle virus.
The complete nucleotide sequences of the RNA-1 segments in broad bean mottle virus (BBMV) and cowpea chlorotic mottle virus (CCMV) were determined. BBMV RNA-1 consists of 3158 nucleotides and CCMV RNA-1 has 3171 nucleotides. Both BBMV and CCMV RNA-1 are capped at the 5' end but, unlike in other tricornaviruses, BBMV RNA-1 initiates with an A residue. Both BBMV and CCMV RNA-1 are monocistronic encoding for highly homologous 1a proteins of 966 and 958 amino acids, respectively. The highest homologies are clustered within two domains: the N-domain that aligns with the nsP1 Sindbis virus protein, a putative methyl transferase, and the C-domain which has a conserved nucleotide binding motif. Previous sequence comparisons suggest that the C-terminal domain may function as an NTP-dependent RNA helicase. In addition, we find that the C-domain has patterns similar to those of the reovirus and vaccinia virus guanylyl transferases. All this implies that 1a protein is a multifunctional polypeptide involved in both RNA capping and RNA polymerization processes.
Dzianott
A M
AM
Northern Illinois University, Department of Biological Sciences, DeKalb 60115.
Bujarski
J J
JJ
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D016384:Consensus Sequence; D016679:Genome, Viral; D008969:Molecular Sequence Data; D016366:Open Reading Frames / Q000235:genetics; D010942:Plant Viruses / Q000235:genetics*; D012328:RNA Viruses / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid; D014764:Viral Proteins / Q000235:genetics
D014764:Viral Proteins