Question

Tobacco mosaic virus self assembles with a long molecule of ________

• A. DNA
• B. RNA
• C. Glucose
• D. Glycerol

Hint:

TMV was the first virus to be crystallized (by Wendell Stanley in 1935), proving that viruses are complex chemical assemblages containing protein and RNA.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Tobacco Mosaic Virus (TMV) is a historic model organism in virology and structural biology.
It is a simple, rod-like virus consisting of a single-stranded genomic nucleic acid core surrounded by a protective protein shell called a capsid.

Step 2: Detailed Explanation:
The genetic material of TMV is a single-stranded RNA molecule of approximately 6,400 nucleotides.
The protein shell is composed of roughly 2,130 identical coat protein subunits arranged in a helical structure.
In a process called self-assembly, the genomic RNA and the coat proteins spontaneously assemble in vitro to form the intact, infectious virus.
The assembly is initiated when a specific loop of the viral RNA, containing the Origin of Assembly (OAs) sequence, inserts into the central cavity of a double-layered disk of coat protein.
As the protein disk converts into a helical conformation, the RNA molecule is pulled into the growing rod, acting as a molecular scaffold that organizes the assembly process.
Because its genome is comprised of ribonucleic acid, the correct molecule with which it self-assembles is RNA.

Step 3: Final Answer:
Tobacco mosaic virus self-assembles with a long molecule of RNA.