The requirement for cobalt in vitamin B12: A paradigm for protein metalation

Vitamin B12, cobalamin, is a cobalt-containing ring-contracted modified tetrapyrrole that represents one of the most complex small molecules made by nature. In prokaryotes it utilised as cofactor, coenzyme, light sensor and gene regulator yet has restricted role in assisting only two enzymes within specific eukaryotes including mammals. This deployment disparity reflected another unique attribute vitamin B12 its biosynthesis limited to certain prokaryotes, with synthesisers pivotal establishing mutualistic microbial communities. The core component cobalamin corrin macrocycle acts main ligand for cobalt. Within this review we investigate why cobalt paired specifically ring, how inserted during biosynthetic process, available cell explore cellular control levels. partitioning exemplifies cells assist metalation.