Evidence for corrin biosynthesis in the last universal common ancestor.

Corrinoids are cobalt-containing tetrapyrroles. They include adenosylcobalamin (vitamin B) and cobamides that function as cofactors and coenzymes for methyl transfer, radical-dependent and redox reactions. Though cobamides are the most complex cofactors in nature, they are essential in the acetyl-CoA pathway, thought to be the most ancient CO-fixation pathway, where they perform a pterin-to-cobalt-to-nickel methyl transfer reaction catalyzed by the corrinoid iron-sulphur protein (CoFeS).

In , a new type of chaperone receives heme from ferrochelatase.

Intracellular heme formation and trafficking are fundamental processes in living organisms. Bacteria and archaea utilize three biogenesis pathways to produce iron protoporphyrin IX (heme ) that diverge after the formation of the common intermediate uroporphyrinogen III (uro'gen III). In this study, we identify and provide a detailed characterization of the enzymes involved in the transformation of uro'gen III into heme in , demonstrating that this bacterium utilizes the protoporphyrin-dependent (PPD) pathway.

Modular structure of complex II: An evolutionary perspective.

Succinate dehydrogenases (SDHs) and fumarate reductases (FRDs) catalyse the interconversion of succinate and fumarate, a reaction highly conserved in all domains of life. The current classification of SDH/FRDs is based on the structure of the membrane anchor subunits and their cofactors. It is, however, unknown whether this classification would hold in the context of evolution.

[Spectral study of the peripheral site of ligand binding in the active center of cholinesterases from different natural sources].

An increased ethidium bromide fluorescence at 610 nm was observed in the presence of cholinesterases from some natural sources, and a new fluorescence band appeared in the 500-570 nm region. The data obtained suggest a resonance energy transfer from the cholinesterase-ethidium bromide complex to a free ethidium bromide molecule. The structure of the peripheral ligand binding sites in the active center of bovine erythrocyte acetylcholinesterase, horse serum butyrylcholinesterase, and squid ganglia cholinesterase proved essentially similar.