Search results
Results from the WOW.Com Content Network
The nucleoid (meaning nucleus-like) is an irregularly shaped region within the prokaryotic cell that contains all or most of the genetic material. [1] [2] [3] The chromosome of a typical prokaryote is circular, and its length is very large compared to the cell dimensions, so it needs to be compacted in order to fit.
Bacterial chromosome, located in the irregularly shaped region known as the nucleoid [5] Extrachromosomal DNA , located outside of the nucleoid region as circular or linear plasmids The bacterial DNA is not packaged using histones to form chromatin as in eukaryotes but instead exists as a highly compact supercoiled structure, the precise nature ...
Prokaryotic genetic material is organized in a simple circular bacterial chromosome in the nucleoid region of the cytoplasm. Eukaryotic genetic material is divided into different, [ 2 ] linear molecules called chromosomes inside a discrete nucleus, usually with additional genetic material in some organelles like mitochondria and chloroplasts ...
The nucleoside base was incorporated uniformly into the bacterial chromosome. He then isolated the chromosomes by lysing the cells gently and placed them on an electron micrograph (EM) grid which he exposed to X-ray film for two months. This Experiment clearly demonstrates the theta replication model of circular bacterial chromosomes. [10]
[27] [28] The nucleoid is a distinct structure and occupies a defined region of the bacterial cell. This structure is, however, dynamic and is maintained and remodeled by the actions of a range of histone-like proteins, which associate with the bacterial chromosome. [29]
Bacteria do not have a membrane-bound nucleus, and their genetic material is typically a single circular bacterial chromosome of DNA located in the cytoplasm in an irregularly shaped body called the nucleoid. [71] The nucleoid contains the chromosome with its associated proteins and RNA.
Extrachromosomal DNA exists in prokaryotes outside the nucleoid region as circular or linear plasmids. Bacterial plasmids are typically short sequences, consisting of 1 to a few hundred kilobase (kb) segments, and contain an origin of replication which allows the plasmid to replicate independently of the bacterial chromosome. [10]
Currently, many more functions of bacteria DNA binding proteins have been discovered, including the regulation of gene expression by histone-like nucleoid-structuring protein, H-NS. H-NS is about 15.6 kDa and assists in the regulation of bacterial transcription in bacteria by repressing and activating certain genes. H-NS binds to DNA with an ...