Explain the structure of TMV.

TMV is a helical long rod like flexible RNA virus.
* Length is 300nm and diameter is 18 nm with molecular weight of 39 × 10⁶ Daltons.
* Capsid contains 2,130 protein subunits arrange in helical fashion. with central hallow space of 4nm called as core.
* Each capsomere is made of single polypeptide chain containing 158 amino acids.
* Inside the core region single stranded spirally coiled RNA with 6,500 nucleotides is present.