Ultraviolet light induces the formation of a cyclobutane ring between adjacent thymines

TLS Online TPP Program

#Id: 3962

#Unit 2. Cellular Organization

Chromosome has to be read under following heads

1. Packaging and packing proteins

2. Supercoiling

3. Loops, domains, centromere and telomere

4. Histones

TLS Online TPP Program

#Id: 3963

#Unit 2. Cellular Organization

The capsid is assembled around the genome for single-stranded RNA viruses in TMV.

TLS Online TPP Program

#Id: 3965

#Unit 2. Cellular Organization

Inserting DNA into a phage head involves two types of reaction:

translocation and condensation. Both are energetically unfavorable.

The genome is packaged into the empty capsid by the terminase enzyme.

TLS Online TPP Program

#Id: 3966

#Unit 2. Cellular Organization

In E.coli, Protein HU is a dimer that condenses DNA, possibly wrapping it into a beadlike structure.

TLS Online TPP Program

#Id: 3967

#Unit 2. Cellular Organization

The bacterial genome consists of a large number of loops of duplex DNA (in the form of a fiber), each of which is secured at the base to form an independent structural domain.

TLS Online TPP Program

#Id: 3968

#Unit 2. Cellular Organization

Each domain consists of -40 kilobases of DNA, or may be smaller, 10 kb each. About -400 domains in the E. coli genome. The ends of the domains appear to be randomly distributed instead of located at predetermined sites on the chromosome.