The Rel homology domain (RHD) is a
protein domain found in a family of eukaryotic
transcription factors,
including both
NF-κB and
NFAT, among others. Some of these transcription factors appear to form multi-protein
DNA-bound complexes.
Phosphorylation
In chemistry, phosphorylation is the attachment of a phosphate group to a molecule or an ion. This process and its inverse, dephosphorylation, are common in biology and could be driven by natural selection. Text was copied from this source, wh ...
of the RHD appears to play a role in the regulation of some of these transcription factors, acting to modulate the expression of their target genes.
The RHD is composed of two
immunoglobulin
An antibody (Ab), also known as an immunoglobulin (Ig), is a large, Y-shaped protein used by the immune system to identify and neutralize foreign objects such as pathogenic bacteria and viruses. The antibody recognizes a unique molecule of the ...
-like
beta barrel subdomains that grip the DNA in the major groove. The
N-terminal
The N-terminus (also known as the amino-terminus, NH2-terminus, N-terminal end or amine-terminus) is the start of a protein or polypeptide, referring to the free amine group (-NH2) located at the end of a polypeptide. Within a peptide, the ami ...
specificity domain resembles the core domain of the
p53 transcription factor, and contains a recognition loop that interacts with DNA bases. In the case of
NF-κB, the
C-terminal dimerization subdomain determines dimerization propensity with other proteins in the
NF-κB/Rel protein family. The dimerization subdomain is immediately followed by a
nuclear localization sequence A nuclear localization signal ''or'' sequence (NLS) is an amino acid sequence that 'tags' a protein for import into the cell nucleus by nuclear transport. Typically, this signal consists of one or more short sequences of positively charged lysines o ...
that also comprises the site for inhibitory interactions with
IκB.
References
Protein domains
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