Holin monooksigenaza

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Holin monooksigenaza
Identifikatori
EC broj 1.14.15.7
CAS broj 118390-76-4
IntEnz IntEnz view
BRENDA BRENDA entry
ExPASy NiceZyme view
KEGG KEGG entry
MetaCyc metabolic pathway
PRIAM profile
PDB RCSB PDB PDBe PDBj PDBsum

Holin monooksigenaza (EC 1.14.15.7, holinska monooksigenaza) je enzim sa sistematskim imenom holin,redukovani-feredoksin:kiseonik oksidoreduktaza.[1][2][3][4][5][6][7] Ovaj enzim katalizuje sledeću hemijsku reakciju:

holin + O2 + 2 redukovani feredoksin + 2 H+ betain aldehid hidrat + H2O + 2 oksidovani feredoksin

Enzim iz španaća, koji je lociran u hloroplastima, sadrži Riskijev tip [2Fe-2S] klastera, kao i mononuklearni Fe centar. Za dejstvo ovog enzima je neophodan Mg2+. On katalizuje prvi korak u sintezi glicin betaina. Kod mnogih bakterija, biljiki i životinja, betain se sintetiše u dva koraka: (1) holin do betainskog aldehida i (2) betainski aldehid do betaina.

Reference[uredi | uredi kod]

  1. Brouquisse, R., Weigel, P., Rhodes, D., Yocum, C.F. and Hanson, A.D. (1989). „Evidence for a ferredoxin-dependent choline monooxygenase from spinach chloroplast stroma”. Plant Physiol. 90: 322-329. PMID 16666757. 
  2. Burnet, M., Lafontaine, P.J. and Hanson, A.D. (1995). „Assay, purification, and partial characterization of choline monooxygenase from spinach”. Plant Physiol. 108: 581-588. PMID 12228495. 
  3. Rathinasabapathi, B., Burnet, M., Russell, B.L., Gage, D.A., Liao, P., Nye, G.J., Scott, P., Golbeck, J.H. and Hanson, A.D. (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. USA 94: 3454-3458. PMID 9096415. 
  4. Russell, B.L., Rathinasabapathi, B. and Hanson, A.D. (1998). „Osmotic stress induces expression of choline monooxygenase in sugar beet and amaranth”. Plant Physiol. 116: 859-865. PMID 9489025. 
  5. Nuccio, M.L., Russell, B.L., Nolte, K.D., Rathinasabapathi, B., Gage, D.A. and Hanson, A.D. (1998). „Glycine betaine synthesis in transgenic tobacco expressing choline monooxygenase is limited by the endogenous choline supply”. Plant J. 16: 101-110. 
  6. Nuccio, M.L., Russell, B.L., Nolte, K.D., Rathinasabapathi, B., Gage, D.A. and Hanson, A.D. (1998). „The endogenous choline supply limits glycine betaine synthesis in transgenic tobacco expressing choline”. Plant J. 16: 487-496. PMID 9881168. 
  7. Waditee, R., Tanaka, Y., Aoki, K., Hibino, T., Jikuya, H., Takano, J., Takabe, T. and 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: 4932-4942. PMID 12466265. 

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