Rautarikkiproteiinit

Rautarikkiproteiinit (Fe-S proteins) are a diverse class of proteins that contain one or more iron-sulfur clusters as prosthetic groups. These clusters are crucial for a wide range of biological functions, including electron transfer, catalysis, and gene regulation. The iron and sulfur atoms in the clusters are typically coordinated by cysteine residues of the protein backbone. The simplest and most common iron-sulfur clusters are [2Fe-2S], [3Fe-4S], and [4Fe-4S] clusters, where the numbers refer to the count of iron and sulfur atoms.

The biosynthesis of iron-sulfur clusters is a complex and highly conserved process, involving dedicated machinery called the iron-sulfur cluster assembly (ISCA) system. This system ensures the correct formation and delivery of these essential cofactors to apoproteins, which are proteins lacking their iron-sulfur clusters. Defects in iron-sulfur cluster biogenesis can lead to severe cellular dysfunction and diseases, highlighting their fundamental importance.

Iron-sulfur proteins are found in all domains of life, from bacteria and archaea to eukaryotes. They play vital roles in numerous metabolic pathways, such as respiration, photosynthesis, nitrogen fixation, and amino acid metabolism. For example, they are key components of the electron transport chain in mitochondria and chloroplasts, essential for ATP production. In some organisms, they also act as sensors, detecting metabolic changes and regulating gene expression accordingly. Their versatile redox properties and catalytic capabilities make them indispensable players in cellular biochemistry.