Part:BBa_K3275000
Arsenic metallothionein
Human arsenic targeting metallothionein
Sequence and Features
- 10COMPATIBLE WITH RFC[10]
- 12COMPATIBLE WITH RFC[12]
- 21INCOMPATIBLE WITH RFC[21]Illegal BamHI site found at 3
- 23COMPATIBLE WITH RFC[23]
- 25COMPATIBLE WITH RFC[25]
- 1000COMPATIBLE WITH RFC[1000]
Introduction
Metallothionein (MT) is a class of small metal-binding proteins that exists in bacteria, plants and animals. These proteins depending on their amino acid compositions have a high binding affinity with different bivalent metal ions. Once MT detects the corresponding metal, it binds the goal through covalent bonds, which are composed of sulfhydryl cysteine residues and stores the metal by tightly chelating the metal. Typically, it is assumed that MTs have two binding domains, one of which is the C-terminal part (α-domain) with three binding sites. The other one is the N-terminal part (β-domain) with four divalent binding sites [1]. Therefore, MTs are important for protecting the cell against heavy metal toxicity and maintaining cellular homeostasis.
Arsenic Metallothionein
Both Ar(III) and As(V) can be catalyzed by arsenate reductase, which allows them to bind to thiol groups easily [2].Metallothionein is a great tool for E.coli to accumulate arsenic because it has a great amount of cysteine, which makes it a thiol-rich protein. This coding sequence for arsenic metallothionein is from rh-MT (recombinant human metallothionein) originally, which can be found in livers and kidneys. The rh-MT has three components: the α Domain, the β domain, and the S-tag, which are shown in Figure 1[3].
In order to make the sequence works in E.coli, specific genetic codes were altered.
Characterization
References
- ↑ Ruttkay-Nedecky, B., Nejdl, L., Gumulec, J., Zitka, O., Masarik, M., Eckschlager, T., … Kizek, R. (2013). The role of metallothionein in oxidative stress. International journal of molecular sciences, 14(3), 6044–6066. doi:10.3390/ijms14036044
- ↑ Ngu, T. and Stillman, M. (2006). Arsenic Binding to Human Metallothionein. Journal of the American Chemical Society, 128(38), pp.12473-12483.
- ↑ Ngu, T. and Stillman, M. (2006). Arsenic Binding to Human Metallothionein. Journal of the American Chemical Society, 128(38), pp.12473-12483.
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