The zinc uptake regulator (Zur)
gene is a
bacterial gene that codes for a
transcription factor protein involved in
zinc homeostasis. The protein is a member of the
ferric uptake regulator family
In molecular biology, the ferric uptake regulator family is a family of bacterial proteins involved in regulating metal ion uptake and in metal homeostasis. The family is named for its founding member, known as the ferric uptake regulator or ferr ...
and binds zinc with high affinity. It typically functions as a
repressor
In molecular genetics, a repressor is a DNA- or RNA-binding protein that inhibits the expression of one or more genes by binding to the operator or associated silencers. A DNA-binding repressor blocks the attachment of RNA polymerase to the ...
of zinc uptake proteins via binding to characteristic
promoter DNA sequences in a
dimer
Dimer may refer to:
* Dimer (chemistry), a chemical structure formed from two similar sub-units
** Protein dimer, a protein quaternary structure
** d-dimer
* Dimer model, an item in statistical mechanics, based on ''domino tiling''
* Julius Dimer ( ...
-of-dimers arrangement that creates strong
cooperativity
Cooperativity is a phenomenon displayed by systems involving identical or near-identical elements, which act dependently of each other, relative to a hypothetical standard non-interacting system in which the individual elements are acting indepen ...
.
Under conditions of zinc deficiency, the protein undergoes a
conformational change
In biochemistry, a conformational change is a change in the shape of a macromolecule, often induced by environmental factors.
A macromolecule is usually flexible and dynamic. Its shape can change in response to changes in its environment or oth ...
that prevents DNA binding, thereby lifting the repression and causing zinc uptake genes such as
ZinT
In molecular biology, ZinT (formerly known as YodA) is a family of protein domains found in prokaryotes. The domain contains a single binding site that can accommodate a divalent cation, with a geometry suggestive of zinc binding. This family ...
and the
ZnuABC
ZnuABC is a high-affinity transporter specialized for transporting zinc ions as part of a system for metal ion homeostasis in bacteria. The complex is a member of the ATP-binding cassette (ABC) transporter protein family. The transporter c ...
zinc transporter to be
expressed.
References
Prokaryote genes
Bacterial proteins
Transcription factors
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