The relaxosome is the
complex of proteins that facilitates
plasmid
A plasmid is a small, extrachromosomal DNA molecule within a cell that is physically separated from chromosomal DNA and can replicate independently. They are most commonly found as small circular, double-stranded DNA molecules in bacteria; how ...
transfer during
bacterial conjugation
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. This takes place through a pilus. It is a parasexual mode of reproduction in bacteri ...
. The proteins are encoded by the
tra operon on a fertility plasmid in the region near the origin of transfer,
oriT Orit is a Hebrew language feminine given name ().
Notable people with this given name include:
*Orit Gadiesh
*Orit Noked
*Orit Strook
*Orit Wolf
*Orit Adato
*Orit Rozin
*Orit Bar-On
*Orit Ishay
*Orit Zuaretz
*Orit Galili-Zucker
Other uses
* The Be ...
. The most important of these proteins is
relaxase, which is responsible for beginning the conjugation process by cutting at the ''nic'' site via
transesterification. This nicking results in a
DNA-
Protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...
complex with the relaxosome bound to a single strand of the plasmid DNA and an exposed 3' hydroxyl group. Relaxase also unwinds the plasmid being conjugated with its
helicase properties. The relaxosome interacts with integration host factors within the oriT.
Other genes that code for relaxosome components include TraH, which stabilizes the relaxosome's structural formation, TraI, which encodes for the relaxase protein, TraJ, which recruits the complex to the oriT site, TraK, which increases the 'nicked' state of the target plasmid, and TraY, which imparts single-stranded DNA character on the oriT site. TraM plays a particularly important role in relaxase interaction by stimulating 'relaxed' DNA formation.
References
*
Molecular biology
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