- Source: Magnesium chelatase
Magnesium-chelatase is a three-component enzyme (EC 6.6.1.1) that catalyses the insertion of Mg2+ into protoporphyrin IX. This is the first unique step in the synthesis of chlorophyll and bacteriochlorophyll. As a result, it is thought that Mg-chelatase has an important role in channeling intermediates into the (bacterio)chlorophyll branch in response to conditions suitable for photosynthetic growth:
The four substrates of this enzyme are ATP, protoporphyrin IX, Mg2+, and H2O; its four products are ADP, phosphate, Mg-protoporphyrin IX, and H+.
This enzyme belongs to the family of ligases, specifically those forming nitrogen-D-metal bonds in coordination complexes. The systematic name of this enzyme class is Mg-protoporphyrin IX magnesium-lyase. Other names in common use include protoporphyrin IX magnesium-chelatase, protoporphyrin IX Mg-chelatase, magnesium-protoporphyrin IX chelatase, magnesium-protoporphyrin chelatase, magnesium-chelatase, Mg-chelatase, and Mg-protoporphyrin IX magnesio-lyase. This enzyme is part of the biosynthetic pathway to chlorophylls.
See also
Biosynthesis of chlorophylls
References
Walker CJ, Weinstein JD (1991). "In vitro assay of the chlorophyll biosynthetic enzyme Mg-chelatase: resolution of the activity into soluble and membrane-bound fractions". Proc. Natl. Acad. Sci. U.S.A. 88 (13): 5789–93. Bibcode:1991PNAS...88.5789W. doi:10.1073/pnas.88.13.5789. PMC 51963. PMID 11607197.
Walker CJ, Willows RD (Oct 15, 1997). "Mechanism and regulation of Mg-chelatase". Biochem. J. 327 (2): 321–33. doi:10.1042/bj3270321. PMC 1218797. PMID 9359397.
Al-Karadaghi S; Hansson, A; Hansson, M; Olsen, JG; Gough, S; Willows, RD; Al-Karadaghi, S (2001). "Interplay between an AAA module and an integrin I domain may regulate the function of magnesium chelatase". J. Mol. Biol. 311 (1): 111–22. doi:10.1006/jmbi.2001.4834. PMID 11469861.
Kata Kunci Pencarian:
- Magnesium chelatase
- Chelatase
- Haloarchaea
- Protoporphyrin IX
- Chlorophyllide
- Cobalt chelatase
- Bilin (biochemistry)
- Ferrochelatase
- Circadian advantage
- List of EC numbers (EC 6)
