Region within a prokaryotic cell containing genetic material
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. In contrast to the nucleus of a eukaryotic cell, it is not surrounded by a nuclear membrane. Instead, the nucleoid forms by condensation and functional arrangement with the help of chromosomal architectural proteins and RNA molecules as well as DNA supercoiling. The length of a genome widely varies (generally at least a few million base pairs) and a cell may contain multiple copies of it.
There is not yet a high-resolution structure known of a bacterial nucleoid, however key features have been researched in Escherichia coli as a model organism. In E. coli, the chromosomal DNA is on average negatively supercoiled and folded into plectonemic loops, which are confined to different physical regions, and rarely diffuse into each other. These loops spatially organize into megabase-sized regions called macrodomains, within which DNA sites frequently interact, but between which interactions are rare. The condensed and spatially organized DNA forms a helical ellipsoid that is radially confined in the cell. The 3D structure of the DNA in the nucleoid appears to vary depending on conditions and is linked to gene expression so that the nucleoid architecture and gene transcription are tightly interdependent, influencing each other reciprocally.
Formation of the Escherichia coli nucleoidA. An illustration of an open conformation of the circular genome of Escherichia coli. Arrows represent bi-directional DNA replication. The genetic position of the origin of bi-directional DNA replication (oriC) and the site of chromosome decatenation (dif) in the replication termination region (ter) are marked. Colors represent specific segments of DNA as discussed in C. B. An illustration of a random coil form adopted by the pure circular DNA of Escherichia coli at thermal equilibrium without supercoils and additional stabilizing factors.[4][5]C. A cartoon of the chromosome of a newly born Escherichia coli cell. The genomic DNA is not only condensed by 1000-fold compared to its pure random coil form but is also spatially organized. oriC and dif are localized in the mid-cell, and specific regions of the DNA indicated by colors in A organize into spatially distinct domains. Six spatial domains have been identified in E. coli. Four domains (Ori, Ter, Left, and Right) are structured and two (NS-right and NS-left) are non-structured. The condensed and organized form of the DNA together with its associated proteins and RNAs is called nucleoid.
^Thanbichler M, Wang SC, Shapiro L (October 2005). "The bacterial nucleoid: a highly organized and dynamic structure". Journal of Cellular Biochemistry. 96 (3): 506–21. doi:10.1002/jcb.20519. PMID 15988757.
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The nucleoid (meaning nucleus-like) is an irregularly shaped region within the prokaryotic cell that contains all or most of the genetic material. The...
prokaryote is held within a DNA/protein complex in the cytosol called the nucleoid, which lacks a nuclear envelope. The complex contains a single, cyclic...
'plastid nucleoids'. Unlike the nucleus of a eukaryotic cell, a plastid nucleoid is not surrounded by a nuclear membrane. The region of each nucleoid may contain...
nuclei. Instead, their DNA is organized into a structure called the nucleoid. The nucleoid is a distinct structure and occupies a defined region of the bacterial...
supercoil domains (SDs). These SDs play a major role in organizing the nucleoid. SDs negatively supercoiled on average but can sometimes be positively...
is held within an irregularly shaped body in the cytoplasm called the nucleoid. The genetic information in a genome is held within genes, and the complete...
between the membranes. The genome of the cell forms a loosely-defined "nucleoid", shown here in yellow, and interacts with many DNA-binding proteins, shown...
chromosome equivalent is called a genophore and is localized within the nucleoid region). The overall structure of the chromatin network further depends...
most prokaryotes have an irregular region that contains DNA, known as the nucleoid. Most prokaryotes have a single, circular chromosome, which is in contrast...
mainly in the cell nucleus. In prokaryotes, the DNA is held within the nucleoid. The genetic information is held within genes, and the complete assemblage...
region of the nucleoid The ParA that was released from the nucleoid behind the plasmid's movement redistributes to other regions of the nucleoid after a delay...
associated with proteins within a central disc structure known as a nucleoid. The nucleoid is surrounded by a membrane and two lateral bodies of unknown function...
located in the cytoplasm in an irregularly shaped body called the nucleoid. The nucleoid contains the chromosome with its associated proteins and RNA. Like...
is produced, or be bound by a ribosome after having moved away from the nucleoid. In contrast, eukaryotes make mRNA in the cell nucleus and then translocate...
naked DNA to the daughter cell, after which it is then surrounded by a nucleoid membrane. However, three-dimensional reconstructions indicate that DNA...
acids, and the citric acid cycle. The DNA molecules are packaged into nucleoids by proteins, one of which is TFAM. The most prominent roles of mitochondria...
age. They are usually packed into nucleoids, which can contain several identical chloroplast DNA rings. Many nucleoids can be found in each chloroplast...
the irregularly shaped region known as the nucleoid Extrachromosomal DNA, located outside of the nucleoid region as circular or linear plasmids The bacterial...
The nucleoid forms an irregular shaped region within a prokaryote cell, containing all or majority of the genetic material to reproduce. The nucleoid controls...
Shuang-Jiang (ed.). "Silver Ions Caused Faster Diffusive Dynamics of Histone-Like Nucleoid-Structuring Proteins in Live Bacteria". Applied and Environmental Microbiology...
the cell to move, ribosomes for the translation of RNA to protein, and a nucleoid that holds all the genetic material in a circular structure. There are...
separate species (E. coli), a gene has a similar function (histone-like nucleoid-structuring protein) but has a separate evolutionary origin and so is an...
migrates to the opposite pole of the cell during replication and before nucleoid separation”. Mutations that affect the formation of the attachment organelle...
separate species (E. coli), a gene has a similar function (histone-like nucleoid-structuring protein) but has a separate evolutionary origin and so is an...
sort of nucleus was once considered to be an intermediate between the nucleoid region of prokaryotes and the true nuclei of eukaryotes, so were termed...
the cytosol contains the cell's genome, within a structure known as a nucleoid. This is an irregular mass of DNA and associated proteins that control...
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