Heme-binding proteins play a variety of critical roles in biology. The functional versatility of this prosthetic
group is attributed to the influence of the polypeptide on the electronic structure and thus reactivity of the heme. NMR
spectroscopy is well suited to simultaneously probe molecular structure, dynamics, and electronic structure of heme proteins
in paramagnetic states. In this review, an overview of recent advances in the heme protein field enabled by NMR
spectroscopy is presented, with a focus on paramagnetic heme proteins. Examples of NMR studies of cytochromes c, globins,
nitrophorins, cytochrome P450, hemophores, and heme oxygenases are discussed. Heme protein biochemistry and
NMR methodology have seen significant advances in the past decade, and it is expected that NMR will continue to play a
central role in our developing understanding of heme protein structure, dynamics, and function.