University:
Swansea University
Course:
PM-133 | Evolutionary and Molecular Genetics
Academic year:

2023
Views:

388

Pages:

4
Author:

Amal J.

Genome Organization in E.coli • distance between 2 base pairs = 0.34 nm • E.coli = 4.6 x 10^6 bp genome length. • total length of genome = 4.6 x 10^6 bp x 0.34 nm = 46 x 10^5 x 34 x 10^-2 nm = 1564 x 10^3 nm = 1.564 x 10^6 nm 1.564 x 10^3 μm=1564μm • E. coli cell = 2 μm • E-coli needs to compact their DNA • no nucleus, only nucleoid Proteins for condensation (2 classes) MUK Muk (BEf)^2 - bridging proteins Class 1. DNA bridging protein - Muk (BEf)^2 Class 2. DNA binding proteins 1→2 HU - heat unstable IHf - integration host factor FIS - factor for inversion stimulation Diameter of E.coli genome = 350μm In human haploid 3.2×10^9 bp DNA diploid- 6.4×10^9 bp length = 2.176×0^9nm DNA double strand: 1) stabilization attractive force: hydrogen bond A=T & G=C, stacking force 2) repulsive force Why more packed in M phase? To prevent entangling and chromosomal breakage In interphase chromosome the transcriptionally active chromatin exist in 11nm and transcriptionally inactive chromatin in 30nm. Maximum condensation in M phase chromosome 700nm, In decondensed form the DNA entagle together, seperation of these entagles generale DNA breakage.