TY - JOUR
T1 - A cooperative oxygen binding hemoglobin from Mycobacterium tuberculosis. Stabilization of heme ligands by a distal tyrosine residue
AU - Yeh, Syun Ru
AU - Couture, Manon
AU - Ouellet, Yannick
AU - Guertin, Michel
AU - Rousseau, Denis L.
PY - 2000/1/21
Y1 - 2000/1/21
N2 - The homodimeric hemoglobin (HbN) from Mycobacterium tuberculosis displays an extremely high oxygen binding affinity and cooperativity. Sequence alignment with other hemoglobins suggests that the proximal F8 ligand is histidine, the distal E7 residue is leucine, and the B10 position is occupied by tyrosine. To determine how these heme pocket residues regulate the ligand binding affinities and physiological functions of HbN, we have measured the resonance Raman spectra of the O2, CO, and OH- derivatives of the wild type protein and the B10 Tyr→ Leu and Phe mutants. Taken together these data demonstrate a unique distal environment in which the heme bound ligands strongly interact with the B10 tyrosine residue. The implications of these data on the physiological functions of HbN and another heme-containing protein, cytochrome c oxidase, are considered.
AB - The homodimeric hemoglobin (HbN) from Mycobacterium tuberculosis displays an extremely high oxygen binding affinity and cooperativity. Sequence alignment with other hemoglobins suggests that the proximal F8 ligand is histidine, the distal E7 residue is leucine, and the B10 position is occupied by tyrosine. To determine how these heme pocket residues regulate the ligand binding affinities and physiological functions of HbN, we have measured the resonance Raman spectra of the O2, CO, and OH- derivatives of the wild type protein and the B10 Tyr→ Leu and Phe mutants. Taken together these data demonstrate a unique distal environment in which the heme bound ligands strongly interact with the B10 tyrosine residue. The implications of these data on the physiological functions of HbN and another heme-containing protein, cytochrome c oxidase, are considered.
UR - http://www.scopus.com/inward/record.url?scp=0034695445&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0034695445&partnerID=8YFLogxK
U2 - 10.1074/jbc.275.3.1679
DO - 10.1074/jbc.275.3.1679
M3 - Article
C2 - 10636862
AN - SCOPUS:0034695445
SN - 0021-9258
VL - 275
SP - 1679
EP - 1684
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 3
ER -