The binding of a cofactor to a protein matrix often involves a reorganization of the polypeptide structure. b Hemoproteins provide multiple examples of this behavior. In this minireview, selected monomeric and single b heme proteins endowed with distinct topological properties are inspected for the extent of induced refolding upon heme binding. To complement the data reported in the literature, original results are presented on a two-on-two globin of cyanobacterial origin (Synechococcus sp. PCC 7002 GlbN) and on the heme-containing module of FixL, an oxygen-sensing protein with the mixed alpha/beta topology of PAS domains. GlbN had a stable apoprotein that was further stabilized and locally refolded by heme binding; in contrast, apoFixLH presented features of a molten globule. Sequence analyses (helicity, disorder, and polarity) and solvent accessibility calculations were performed to identify trends in the architecture of b hemoproteins. In several cases, the primary structure appeared biased toward a partially disordered binding pocket in the absence of the cofactor.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.