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.
Freitas
Tracey Allen K
TA
Department of Microbiology, Snyder Hall 207, 2538 The Mall, University of Hawaii, Honolulu, HI 96822, USA.
Hou
Shaobin
S
Dioum
Elhadji M
EM
Saito
Jennifer A
JA
Newhouse
James
J
Gonzalez
Gonzalo
G
Gilles-Gonzalez
Marie-Alda
MA
Alam
Maqsudul
M
D000595:Amino Acid Sequence; D001105:Archaea / Q000737:chemistry*; D001483:Base Sequence; D002248:Carbon Monoxide / Q000378:metabolism; D017931:DNA Primers; D006454:Hemoglobins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009569:Nitric Oxide / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism; D010802:Phylogeny; D011485:Protein Binding; D011487:Protein Conformation; D017386:Sequence Homology, Amino Acid; D013056:Spectrophotometry, Ultraviolet
D017931:DNA Primers; D006454:Hemoglobins; D009569:Nitric Oxide; D002248:Carbon Monoxide; D010100:Oxygen