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פותח על ידי קלירמאש פתרונות בע"מ -
Purification and characterization of sulfide-quinone reductase, a novel enzyme driving anoxygenic photosynthesis in Oscillatoria limnetica
Year:
1994
Source of publication :
Journal of Biological Chemistry
Authors :
שחק, יוספה
;
.
Volume :
269
Co-Authors:
Arieli, B., Div. of Microbial and Molec. Ecology, Institute of Life Sciences, Hebrew University of Jerusalem, 91904 Jerusalem, Israel, Dept. of Biological Sciences, Purdue University, West Lafayette, IN 47907, United States
Shahak, Y., Institute of Horticulture, Volcani Center, Agricultural Research Organization, P. O. Box 6, 50250 Bet-Dagan, Israel
Taglicht, D., Div. of Microbial and Molec. Ecology, Institute of Life Sciences, Hebrew University of Jerusalem, 91904 Jerusalem, Israel, Dept. of Cell Biology and Anatomy, Johns Hopkins Univ., School of Medicine, 725 N. Wolfe St, Baltimore, MD 21205-2196, United States
Hauska, G., Lehrst. F. Zellbiologie P., Universität Regensburg, 8400 Regensburg, Germany
Padan, E.
Facilitators :
From page:
5705
To page:
5711
(
Total pages:
7
)
Abstract:
An enzyme catalyzing sulfide quinone oxido-reduction (E.C.1.8.5.'.; SQR) has been purified in an active form, from thylakoids of the cyanobacterium Oscillatoria limnetica. It is composed of a single polypeptide of about 57 kDa. The catalytic activity of the purified enzyme is similar to the membrane-bound form in its kinetic parameters: apparent K(m) for sulfide equals 8 μM; V(max) of 100-150 μmol of plastoquinone-1 reduced/mg protein/h; quinone-substrate specificity; differential sensitivity to quinone analog inhibitors, the most potent of which being aurachin C (I50 = 7 nM), and specific inducibility by sulfide. Taken together, they suggest that the purified SQR is the enzyme catalyzing anoxygenic photosynthesis in cyanobacteria. The UV and visible absorption and fluorescence spectra of the purified SQR are typical of a flavoprotein. Both the absorption and fluorescence intensities are reduced by sulfide. The SQR activity is inhibited by KCN, a flavoprotein inhibitor. We have sequenced so far 29 amino acid residues of the SQR NH2 terminus and found that from the second residue, this sequence contains the highly conserved fingerprint of the NAD/FAD-binding domain of many NAD/FAD-binding enzymes (Wierenga, R. K., Terpstra, P., and Hol, W. G. S. (1986) J. Mol. Biol. 187, 101-107). This suggests that the SQR enzyme is a flavoprotein which contains binding sites for sulfide and quinone and that the electron transfer between the two is mediated by FAD.
Note:
Related Files :
Chromatography, High Pressure Liquid
nicotinamide adenine dinucleotide
photosynthesis
Sequence Homology, Amino Acid
עוד תגיות
תוכן קשור
More details
DOI :
Article number:
Affiliations:
Database:
סקופוס
Publication Type:
מאמר
;
.
Language:
אנגלית
Editors' remarks:
ID:
25552
Last updated date:
02/03/2022 17:27
Creation date:
17/04/2018 00:15
Scientific Publication
Purification and characterization of sulfide-quinone reductase, a novel enzyme driving anoxygenic photosynthesis in Oscillatoria limnetica
269
Arieli, B., Div. of Microbial and Molec. Ecology, Institute of Life Sciences, Hebrew University of Jerusalem, 91904 Jerusalem, Israel, Dept. of Biological Sciences, Purdue University, West Lafayette, IN 47907, United States
Shahak, Y., Institute of Horticulture, Volcani Center, Agricultural Research Organization, P. O. Box 6, 50250 Bet-Dagan, Israel
Taglicht, D., Div. of Microbial and Molec. Ecology, Institute of Life Sciences, Hebrew University of Jerusalem, 91904 Jerusalem, Israel, Dept. of Cell Biology and Anatomy, Johns Hopkins Univ., School of Medicine, 725 N. Wolfe St, Baltimore, MD 21205-2196, United States
Hauska, G., Lehrst. F. Zellbiologie P., Universität Regensburg, 8400 Regensburg, Germany
Padan, E.
Purification and characterization of sulfide-quinone reductase, a novel enzyme driving anoxygenic photosynthesis in Oscillatoria limnetica
An enzyme catalyzing sulfide quinone oxido-reduction (E.C.1.8.5.'.; SQR) has been purified in an active form, from thylakoids of the cyanobacterium Oscillatoria limnetica. It is composed of a single polypeptide of about 57 kDa. The catalytic activity of the purified enzyme is similar to the membrane-bound form in its kinetic parameters: apparent K(m) for sulfide equals 8 μM; V(max) of 100-150 μmol of plastoquinone-1 reduced/mg protein/h; quinone-substrate specificity; differential sensitivity to quinone analog inhibitors, the most potent of which being aurachin C (I50 = 7 nM), and specific inducibility by sulfide. Taken together, they suggest that the purified SQR is the enzyme catalyzing anoxygenic photosynthesis in cyanobacteria. The UV and visible absorption and fluorescence spectra of the purified SQR are typical of a flavoprotein. Both the absorption and fluorescence intensities are reduced by sulfide. The SQR activity is inhibited by KCN, a flavoprotein inhibitor. We have sequenced so far 29 amino acid residues of the SQR NH2 terminus and found that from the second residue, this sequence contains the highly conserved fingerprint of the NAD/FAD-binding domain of many NAD/FAD-binding enzymes (Wierenga, R. K., Terpstra, P., and Hol, W. G. S. (1986) J. Mol. Biol. 187, 101-107). This suggests that the SQR enzyme is a flavoprotein which contains binding sites for sulfide and quinone and that the electron transfer between the two is mediated by FAD.
Scientific Publication
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