Class of enzymes
In enzymology , a choline monooxygenase (EC 1.14.15.7 ) is an enzyme that catalyzes the chemical reaction
choline + O2 + 2 reduced ferredoxin + 2 H+
⇌
{\displaystyle \rightleftharpoons }
betaine aldehyde hydrate + H2 O + 2 oxidized ferredoxin
The 4 substrates of this enzyme are choline , O2 , reduced ferredoxin , and H+ , whereas its 3 products are betaine aldehyde hydrate , H2 O , and oxidized ferredoxin .
This enzyme belongs to the family of oxidoreductases , specifically those acting on paired donors, with O2 as oxidant and incorporation or reduction of oxygen. The oxygen incorporated need not be derived from O2 with reduced iron-sulfur protein as one donor, and incorporation o one atom of oxygen into the other donor. The systematic name of this enzyme class is choline, reduced-ferredoxin:oxygen oxidoreductase . This enzyme participates in glycine, serine and threonine metabolism .
References
Brouquisse R, Weigel P, Rhodes D, Yocum CF, Hanson AD (1989). "Evidence for a ferredoxin-dependent choline monooxygenase from spinach chloroplast stroma" . Plant Physiol . 90 (1): 322– 329. doi :10.1104/pp.90.1.322 . PMC 1061717 . PMID 16666757 .
Burnet M, Lafontaine PJ, Hanson AD (1995). "Assay, Purification, and Partial Characterization of Choline Monooxygenase from Spinach" . Plant Physiol . 108 (2): 581– 588. doi :10.1104/pp.108.2.581 . PMC 157377 . PMID 12228495 .
Scott P, Golbeck JH, Hanson AD (1997). "Choline monooxygenase, an unusual iron-sulfur enzyme catalyzing the first step of glycine betaine synthesis in plants: prosthetic group characterization and cDNA cloning" . Proc. Natl. Acad. Sci. U.S.A . 94 (7): 3454– 8. Bibcode :1997PNAS...94.3454R . doi :10.1073/pnas.94.7.3454 . PMC 20391 . PMID 9096415 .
Russell BL, Rathinasabapathi B, Hanson AD (1998). "Osmotic stress induces expression of choline monooxygenase in sugar beet and amaranth" . Plant Physiol . 116 (2): 859– 65. doi :10.1104/pp.116.2.859 . PMC 35146 . PMID 9489025 .
Gage DA, Hanson AD (1998). "Glycine betaine synthesis in transgenic tobacco expressing choline monooxygenase is limited by the endogenous choline supply". Plant J . 16 (1): 101– 110. doi :10.1046/j.1365-313x.1998.00274.x .
AD; Russell, BL; Nolte, KD; Rathinasabapathi, B; Gage, DA; Hanson, AD (1998). "The endogenous choline supply limits glycine betaine synthesis in transgenic tobacco expressing choline monooxygenase" . Plant J . 16 (4): 487– 96. doi :10.1046/j.1365-313x.1998.00316.x . PMID 9881168 .
Takabe T; Tanaka, Y; Aoki, K; Hibino, T; Jikuya, H; Takano, J; Takabe, T; Takabe, T (2003). "Isolation and functional characterization of N-methyltransferases that catalyze betaine synthesis from glycine in a halotolerant photosynthetic organism Aphanothece halophytica" . J. Biol. Chem . 278 (7): 4932– 42. doi :10.1074/jbc.M210970200 . PMID 12466265 .
Activity Regulation Classification Kinetics Types