Book contents
- Frontmatter
- Contents
- List of contributors
- Editors' preface
- Conference participants
- 1 Introduction and guide
- Part I The impact of viral diseases
- Part II Origins of viruses and their genes
- Part III Sources of virus variation
- Part IV Molecular interactions of viruses and their hosts
- Part V Viruses, hosts and populations
- Part VI Case studies of viral taxa; their systematics and evolution
- 18 Evolution of poxviruses and African swine fever virus
- 19 Molecular systematics of the flaviviruses and their relatives
- 20 Herpesviridae
- 21 Aphthovirus evolution
- 22 Evolution of the Bunyaviridae
- 23 Evolution of the tobamoviruses
- 24 The luteovirus supergroup: rampant recombination and persistent partnerships
- 25 The evolution of the Reoviridae
- 26 Genetic variation and evolution of satellite viruses and satellite RNAs
- 27 Molecular evolution of the retroid family
- 28 Adaptation of members of the Orthomyxoviridae family to transmission by ticks Patricia
- 29 The Order Mononegavirales: evolutionary relationships and mechanisms of variation
- 30 The molecular evolution of the human immunodeficiency viruses
- 31 Molecular evolution of papillomaviruses
- 32 Molecular systematics of the Potyviridae, the largest plant virus family
- 33 Evolution of alphaviruses
- 34 Evolution of influenza viruses: rapid evolution and stasis
- Part VII Techniques for viral systematics
- Index
23 - Evolution of the tobamoviruses
Published online by Cambridge University Press: 04 May 2010
- Frontmatter
- Contents
- List of contributors
- Editors' preface
- Conference participants
- 1 Introduction and guide
- Part I The impact of viral diseases
- Part II Origins of viruses and their genes
- Part III Sources of virus variation
- Part IV Molecular interactions of viruses and their hosts
- Part V Viruses, hosts and populations
- Part VI Case studies of viral taxa; their systematics and evolution
- 18 Evolution of poxviruses and African swine fever virus
- 19 Molecular systematics of the flaviviruses and their relatives
- 20 Herpesviridae
- 21 Aphthovirus evolution
- 22 Evolution of the Bunyaviridae
- 23 Evolution of the tobamoviruses
- 24 The luteovirus supergroup: rampant recombination and persistent partnerships
- 25 The evolution of the Reoviridae
- 26 Genetic variation and evolution of satellite viruses and satellite RNAs
- 27 Molecular evolution of the retroid family
- 28 Adaptation of members of the Orthomyxoviridae family to transmission by ticks Patricia
- 29 The Order Mononegavirales: evolutionary relationships and mechanisms of variation
- 30 The molecular evolution of the human immunodeficiency viruses
- 31 Molecular evolution of papillomaviruses
- 32 Molecular systematics of the Potyviridae, the largest plant virus family
- 33 Evolution of alphaviruses
- 34 Evolution of influenza viruses: rapid evolution and stasis
- Part VII Techniques for viral systematics
- Index
Summary
Introduction
The tobamovirus group of plant viruses has 12 recognized members (Francki et al., 1991) sharing the following characteristics: infective particles are very stable, rigid rods, of about 300 × 18 nm, with a sedimentation coefficient of 190 S; each particle is built of about 2000 protein subunits of a single molecular species (Mr 17–18 × 103), helically (pitch 2.3 nm) arranged together with a monopartite, single-stranded, genomic RNA (Mr 2 × 106, or ∼ 6.5 kb) of messenger polarity.
The genomic RNA (gRNA) encodes at least four proteins: gRNA is the mRNA for a 126 kD protein (126 K), whose open reading frame (ORF) initiates 60-71 nt from the capped 5′ end, and for a readthrough protein of 183 kD (183 K). Both the 126 K and the 183 K are required for viral RNA replication, and found in them are consensus sequences for methyltransferases and helicases in the 126 K and for RNA-polymerases, in the 54 kD (54 K) readthrough portion of the 183 K. A third ORF encodes a 30 kD protein (MP), required for the cell-to-cell movement of the virus in the plant; the fourth ORF encodes the coat protein (CP). To the 3′ side of the CP ORF, there is a non-coding region (3′ ncr) 179-414 nt long, that may adopt a tRNA-like configuration and can be amino-acylated, for most tobamoviruses, with histidine. Both MP, CP (and perhaps the 54 K readthrough part of the 183 K), are translated from 3′ -coterminal subgenomic RNAs produced during replication.
- Type
- Chapter
- Information
- Molecular Basis of Virus Evolution , pp. 338 - 350Publisher: Cambridge University PressPrint publication year: 1995
- 6
- Cited by