(N.B. a function is associated to the site as a whole, not to each metal within the site)
When the metal ion is directly involved in the reaction mechanism of the enzyme.
When the metal ion partecipates to the reaction mechanism by donating/accepting electron(s).
- Not Redox
When the metal ion participates to the reaction mechanism, but maintains its redox number throughout the reaction.
when the metal ion stabilizes the 3D or higher-order structure of the macromolecule
it may aim to stabilize:
- The tertiary structure of a biomolecule
- The quaternary structure of a protein
- The complex interface of biomolecules
When the metal ion binds other chemical species that are then transported together with it and eventually released.
- Electron Transfer
When the metal ion transports electrons.
When the metal ion is involved in controlling the activity of the system or in the regulation of cellular processes.
it may control:
When the binding of the metal ion enhances/inhibits the activity of an enzyme.
When the binding of the metal ion induces/inhibits transcription.
When the metal ion is the target of the protein.
it may aim to:
- Sense the presence of the metal or of a metal-containing cofactor
- Trasport the metal or a metal-containing cofactor
- Store the metal or a metal-containing cofactor
- Degradate a metal-containing cofactor
- Biosynthesize a metal-containing cofactor
when the metal ion has the aim of preserving and defending a molecule from adverse reactions