Search results
Results From The WOW.Com Content Network
DNA gyrase, or simply gyrase, is an enzyme within the class of topoisomerase and is a subclass of Type II topoisomerases [1] that reduces topological strain in an ATP dependent manner while double-stranded DNA is being unwound by elongating RNA-polymerase [2] or by helicase in front of the progressing replication fork.
Type II topoisomerases increase or decrease the linking number of a DNA loop by 2 units, and it promotes chromosome disentanglement. For example, DNA gyrase, a type II topoisomerase observed in E. coli and most other prokaryotes, introduces negative supercoils and decreases the linking number by 2.
The process of bacterial cell division is defined as binary fission, where a bacterium splits to produce two daughter cells. [4] This division occurs during cytokinesis, which in bacteria is made possible due to the divisome (a specific large protein complex) and FtsZ (the ancestor to tubulin for bacteria that drives cytokinesis itself). [4]
A negatively supercoiled DNA molecule will produce either a one-start left-handed helix, the toroid, or a two-start right-handed helix with terminal loops, the plectoneme. Plectonemes are typically more common in nature, and this is the shape most bacterial plasmids will take.
With DNA in its "relaxed" state, a strand usually circles the axis of the double helix once every 10.4 base pairs, but if the DNA is twisted the strands become more tightly or more loosely wound. [43] If the DNA is twisted in the direction of the helix, this is positive supercoiling, and the bases are held more tightly together.
Bacterial conjugation is the transfer of genetic material between bacterial cells by direct cell-to-cell contact or by a bridge-like connection between two cells. [1] This takes place through a pilus. [2] [full citation needed] It is a parasexual mode of reproduction in bacteria. Escherichia coli conjugating using F-pili. These long and robust ...
There are two main types of bacterial cell walls, those of Gram-positive bacteria and those of Gram-negative bacteria, which are differentiated by their Gram staining characteristics. For both these types of bacteria, particles of approximately 2 nm can pass through the peptidoglycan. [3]
Bacterial conjugation is the transfer of genetic material (plasmid) between bacterial cells by direct cell-to-cell contact or by a bridge-like connection between two cells. [1] Discovered in 1946 by Joshua Lederberg and Edward Tatum, [ 2 ] conjugation is a mechanism of horizontal gene transfer as are transformation and transduction although ...