Origin recognition complex subunit 1 is a
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...
that in humans is encoded by the ORC1
gene
In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...
.
It is closely related to
CDC6
Cell division control protein 6 homolog is a protein that in humans is encoded by the ''CDC6'' gene.
The protein encoded by this gene is highly similar to Saccharomyces cerevisiae Cdc6, a protein essential for the initiation of DNA replication. ...
, and both are the same protein in
archaea
Archaea ( ) is a Domain (biology), domain of organisms. Traditionally, Archaea only included its Prokaryote, prokaryotic members, but this has since been found to be paraphyletic, as eukaryotes are known to have evolved from archaea. Even thou ...
.
Function
The
origin recognition complex
In molecular biology, origin recognition complex (ORC) is a multi-subunit DNA binding complex (6 subunits) that binds in all eukaryotes and archaea in an Adenosine triphosphate, ATP-dependent manner to origins of replication. The subunits of this ...
(ORC) is a highly conserved six subunits protein complex essential for the initiation of the
DNA replication
In molecular biology, DNA replication is the biological process of producing two identical replicas of DNA from one original DNA molecule. DNA replication occurs in all life, living organisms, acting as the most essential part of heredity, biolog ...
in eukaryotic cells. Studies in yeast demonstrated that ORC binds specifically to origins of replication and serves as a platform for the assembly of the
pre-replication complex
A pre-replication complex (pre-RC) is a protein complex that forms at the origin of replication during the initiation step of DNA replication. Formation of the pre-RC is required for DNA replication to occur. Complete and faithful replication of ...
, which includes additional initiation factors such as
Cdc6
Cell division control protein 6 homolog is a protein that in humans is encoded by the ''CDC6'' gene.
The protein encoded by this gene is highly similar to Saccharomyces cerevisiae Cdc6, a protein essential for the initiation of DNA replication. ...
and
Mcm proteins. The protein encoded by this gene is the largest subunit of the origin recognition complex. While other ORC subunits are stable throughout the
cell cycle
The cell cycle, or cell-division cycle, is the sequential series of events that take place in a cell (biology), cell that causes it to divide into two daughter cells. These events include the growth of the cell, duplication of its DNA (DNA re ...
, the levels of this protein vary during the cell cycle, which has been shown to be controlled by
ubiquitin-mediated proteolysis after initiation of DNA replication. This protein is found to be selectively
phosphorylated
In biochemistry, phosphorylation is described as the "transfer of a phosphate group" from a donor to an acceptor. A common phosphorylating agent (phosphate donor) is ATP and a common family of acceptor are alcohols:
:
This equation can be writt ...
during
mitosis
Mitosis () is a part of the cell cycle in eukaryote, eukaryotic cells in which replicated chromosomes are separated into two new Cell nucleus, nuclei. Cell division by mitosis is an equational division which gives rise to genetically identic ...
. It is also reported to interact with
MYST histone acetyltransferase 2 (MYST2/HBO1), a protein involved in control of transcription silencing.
Interactions
ORC1 has been shown to
interact with:
*
CDC45-related protein[ and
* ]CDC6
Cell division control protein 6 homolog is a protein that in humans is encoded by the ''CDC6'' gene.
The protein encoded by this gene is highly similar to Saccharomyces cerevisiae Cdc6, a protein essential for the initiation of DNA replication. ...
,[
* ]Cyclin-dependent kinase 2
Cyclin-dependent kinase 2, also known as cell division protein kinase 2, or Cdk2, is an enzyme that in humans is encoded by the ''CDK2'' gene. The protein encoded by this gene is a member of the cyclin-dependent kinase family of Ser/Thr protein ...
,[
* MCM2,][
* MCM4,][
* MCM6,][
* ]MCM7
DNA replication licensing factor MCM7 is a protein that in humans is encoded by the ''MCM7'' gene.
Function
The protein encoded by this gene is one of the highly conserved mini-chromosome maintenance proteins (MCM) that are essential for the i ...
,[
* MYST2,][
* ORC5,][ and
* ]SKP2
S-phase kinase-associated protein 2 is an enzyme that in humans is encoded by the ''SKP2'' gene.
Structure and function
Skp2 contains 424 residues in total with the ~40 amino acid F-box domain lying closer to the N-terminal region at the 94-1 ...
.[
]
References
Further reading
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External links
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{{DNA replication