Ancestral hemoglobins in Archaea.


Hemoglobins are ubiquitous in Eukarya and Bacteria but, until now, have not been found in Archaea. A phylogenetic analysis of the recently revealed microbial family of globin-coupled heme-based sensors suggests that these sensors descended from an ancient globin-only progenitor, or a protoglobin (Pgb). Here, we report the discovery and characterization of two Pgbs from the Archaea: ApPgb from the obligately aerobic hyperthermophile Aeropyrum pernix, and MaPgb from the strictly anaerobic methanogen Methanosarcina acetivorans. Both ApPgb and MaPgb bind molecular oxygen, nitric oxide, and carbon monoxide by means of a heme moiety that is coordinated to the protein through the F8 histidine (histidine 120). We postulate that these archaeal globins are the ancestors of contemporary hemoglobins.

7 Figures and Tables

Citations per Year

117 Citations

Semantic Scholar estimates that this publication has 117 citations based on the available data.

See our FAQ for additional information.

Cite this paper

@article{Freitas2004AncestralHI, title={Ancestral hemoglobins in Archaea.}, author={Tracey Allen K Freitas and Shaobin Hou and Elhadji M. Dioum and Jennifer A. Saito and James S. Newhouse and Gonzalo Gonz{\'a}lez and Marie-Alda Gilles-Gonzalez and Maqsudul Alam}, journal={Proceedings of the National Academy of Sciences of the United States of America}, year={2004}, volume={101 17}, pages={6675-80} }