[Structure and function of metallothionein]

Area of Science:

• Biochemistry
• Molecular Biology

Context:

• Metallothioneins (MTs) are low molecular weight proteins characterized by high cysteine and heavy metal content.
• Despite lacking enzymatic activity, MTs perform crucial roles including metal chelation, radical scavenging, and cell proliferation regulation.

Purpose:

• To elucidate the multifunctional roles of metallothioneins in biological systems.
• To describe the structural basis of MT function, including metal-sulfur bonds and cluster formation.
• To highlight the induction and gene regulation mechanisms of MTs.

Summary:

• MTs bind toxic and essential metals via metal-sulfur bonds within alpha and beta clusters, involving specific cysteinyl residues.
• Their expression can be induced by various stimuli like metals, chemicals, and stress.
• The well-understood gene structure and regulation facilitate their use in controlling gene expression.

Impact:

• Understanding MTs aids in developing strategies for heavy metal detoxification and managing oxidative stress.
• Research using transgenic and knockout mice provides insights into MTs' in vivo functions.
• The regulatory elements of MT genes are valuable tools in genetic engineering and biotechnology.