DNA damage-binding protein 1 is a
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 ...
that in humans is encoded by the ''DDB1''
gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...
.
Gene
The gene's position is on chromosome 11q12-q13.
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Protein
The DDB1 gene encodes the large subunit of DNA damage-binding protein, a heterodimer
In biochemistry, a protein dimer is a macromolecular complex formed by two protein monomers, or single proteins, which are usually non-covalently bound. Many macromolecules, such as proteins or nucleic acids, form dimers. The word ''dimer'' has ...
composed of a large and a small ( DDB2) subunit. DDB1 contains 1140 amino acids, amounting to a mass of 127 kDa.[
]
Function
As its name suggests, DDB1 was initially implicated in the process of a specific type of DNA repair known as nucleotide excision repair
Nucleotide excision repair is a DNA repair mechanism. DNA damage occurs constantly because of chemicals (e.g. intercalating agents), radiation and other mutagens. Three excision repair pathways exist to repair single stranded DNA damage: Nucle ...
. Since then, researchers have found that DDB1 primarily functions as a core component of the CUL4A
Cullin-4A is a protein that in humans is encoded by the ''CUL4A'' gene. CUL4A belongs to the cullin family of ubiquitin ligase proteins and is highly homologous to the CUL4B protein. CUL4A regulates numerous key processes such as DNA repair, chro ...
- and CUL4B-based E3 ubiquitin ligase
A ubiquitin ligase (also called an E3 ubiquitin ligase) is a protein that recruits an E2 ubiquitin-conjugating enzyme that has been loaded with ubiquitin, recognizes a protein substrate, and assists or directly catalyzes the transfer of ubiquitin ...
complexes. DDB1 serves as a bridge or adaptor protein which interacts with dozens of proteins known as DDB1 and CUL4-associated factors (DCAFs). These DCAFs are often ubiquitin ligase substrates and regulate numerous essential processes in the cell including DNA repair (DDB2), DNA replication, chromatin remodeling ( Cdt2) and more.
Interactions
DDB1 has been shown to interact
Advocates for Informed Choice, dba interACT or interACT Advocates for Intersex Youth, is a 501(c)(3) nonprofit organization using innovative strategies to advocate for the legal and human rights of children with intersex traits. The organizati ...
with Transcription initiation protein SPT3 homolog
Transcription initiation protein SPT3 homolog is a protein that in humans is encoded by the ''SUPT3H'' gene.
Interactions
Transcription initiation protein SPT3 homolog has been shown to interact with GCN5L2, TAF6L, TADA3L, TAF5L, SF3B3, SUPT7L ...
, GCN5L2
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Histone acetyltransferase KAT2A is an enzyme that in humans is encoded by the ''KAT2A'' gene.
Interactions
GCN5L2 has been shown to interact with:
* DDB1,
* Ku70,
* Ku80
Ku80 is a protein that, in humans, is encoded by the ''XRCC5 ...
, DDB2, CUL4A
Cullin-4A is a protein that in humans is encoded by the ''CUL4A'' gene. CUL4A belongs to the cullin family of ubiquitin ligase proteins and is highly homologous to the CUL4B protein. CUL4A regulates numerous key processes such as DNA repair, chro ...
,[ CUL4B][ and ]P21
p21Cip1 (alternatively p21Waf1), also known as cyclin-dependent kinase inhibitor 1 or CDK-interacting protein 1, is a cyclin-dependent kinase inhibitor (CKI) that is capable of inhibiting all cyclin/CDK complexes, though is primarily associated ...
.
References
Further reading
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{{DNA repair