A cooperative oxygen-binding hemoglobin from Mycobacterium tuberculosis.
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ABSTRACT:
SUBMITTER: Couture M
PROVIDER: S-EPMC18015 | biostudies-literature | 1999 Sep
REPOSITORIES: biostudies-literature
Publications
A cooperative oxygen-binding hemoglobin from Mycobacterium tuberculosis.
Couture M M Yeh S R SR Wittenberg B A BA Wittenberg J B JB Ouellet Y Y Rousseau D L DL Guertin M M
Proceedings of the National Academy of Sciences of the United States of America 19990901 20
Two putative hemoglobin genes, glbN and glbO, were recently discovered in the complete genome sequence of Mycobacterium tuberculosis H37Rv. Here, we show that the glbN gene encodes a dimeric hemoglobin (HbN) that binds oxygen cooperatively with very high affinity (P(50) = 0.013 mmHg at 20 degrees C) because of a fast combination (25 microM(-1).s(-1)) and a slow dissociation (0.2 s(-1)) rate. Resonance Raman spectroscopy and ligand association/dissociation kinetic measurements, along with mutagen ...[more]
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