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Any constituent part of the cytoplasm, all of the contents of a cell excluding the plasma membrane and nucleus, but including other subcellular structures. Any macromolecular complex composed of two or more polypeptide subunits, which may or may not be identical. Protein complexes may have other associated non-protein prosthetic groups, such as nucleotides, metal ions or other small molecules. All of the contents of a cell excluding the plasma membrane and nucleus, but including other subcellular structures. A stable assembly of two or more macromolecules, i.e. proteins, nucleic acids, carbohydrates or lipids, in which the constituent parts function together. Any constituent part of the living contents of a cell; the matter contained within (but not including) the plasma membrane, usually taken to exclude large vacuoles and masses of secretory or ingested material. In eukaryotes it includes the nucleus and cytoplasm. A multisubunit complex composed of two copies of a restriction (R) subunit, two copies of a methylation (M) subunit, and one copy of a specificity (S) subunit. This complex recognizes specific short DNA sequences (through the S subunit), and binds to them. If the recognition site is hemimethylated, the complex acts as a methyltransferase which modifies the recognition site, using S-adenosylmethionine as the methyl donor. Only the M and S subunits are required for this reaction. If the complex binds to an unmethylated recognition site, then the complex translocates the DNA bidirectionally in an ATP-dependent manner. When the translocation is stalled by impact with another complex or unusual DNA structure, the enzyme functions as an endonuclease and cleavage of the DNA will occur, hundreds or thousands of base pairs away from the recognition site. These DNA restriction systems are used by bacteria to defend against phage and other foreign DNA that may enter a cell.

View Gene Ontology (GO) Term

GO TERM SUMMARY
Name: Type I site-specific deoxyribonuclease complex
Acc: GO:0019812
Aspect: Cellular Component
Desc: A multisubunit complex composed of two copies of a restriction (R) subunit, two copies of a methylation (M) subunit, and one copy of a specificity (S) subunit. This complex recognizes specific short DNA sequences (through the S subunit), and binds to them. If the recognition site is hemimethylated, the complex acts as a methyltransferase which modifies the recognition site, using S-adenosylmethionine as the methyl donor. Only the M and S subunits are required for this reaction. If the complex binds to an unmethylated recognition site, then the complex translocates the DNA bidirectionally in an ATP-dependent manner. When the translocation is stalled by impact with another complex or unusual DNA structure, the enzyme functions as an endonuclease and cleavage of the DNA will occur, hundreds or thousands of base pairs away from the recognition site. These DNA restriction systems are used by bacteria to defend against phage and other foreign DNA that may enter a cell.
Synonyms:
  • Type I restriction enzyme complex
Proteins in PDR annotated with:
   This term: 13 [Search]
   Term or descendants: 13 [Search]


[geneontology.org]
INTERACTIVE GO GRAPH

GO:0019812 - Type I site-specific deoxyribonuclease complex (interactive image map)
YRC Informatics Platform - Version 3.0
Created and Maintained by: Michael Riffle