Reaction: malonate semialdehyde + CoA + NADP+ = malonyl-CoA + NADPH + H+
For diagram of reaction click here (another example).
Other name(s): NADP-dependent malonyl CoA reductase; malonyl CoA reductase (NADP); malonyl CoA reductase (malonate semialdehyde-forming)
Systematic name: malonate semialdehyde:NADP+ oxidoreductase (malonate semialdehyde-forming)
Comments: Requires Mg2+. Catalyses the reduction of malonyl-CoA to malonate semialdehyde, a key step in the 3-hydroxypropanoate and the 3-hydroxypropanoate/4-hydroxybutanoate cycles, autotrophic CO2 fixation pathways found in some green non-sulfur phototrophic bacteria and some thermoacidophilic archaea, respectively [1,2]. The enzyme from Sulfolobus tokodaii has been purified, and found to contain one RNA molecule per two subunits [3]. The enzyme from Chloroflexus aurantiacus is bifunctional, and also catalyses the next reaction in the pathway, EC 1.1.1.298 [3-hydroxypropionate dehydrogenase (NADP+)] [4].
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:
References:
1. Strauss, G. and Fuchs, G. Enzymes of a novel autotrophic CO2 fixation pathway in the phototrophic bacterium Chloroflexus aurantiacus, the 3-hydroxypropionate cycle. Eur. J. Biochem. 215 (1993) 633-643. [PMID: 8354269]
2. Berg, I.A., Kockelkorn, D., Buckel, W. and Fuchs, G. A 3-hydroxypropionate/4-hydroxybutyrate autotrophic carbon dioxide assimilation pathway in Archaea. Science 318 (2007) 1782-1786. [PMID: 18079405]
3. Alber, B., Olinger, M., Rieder, A., Kockelkorn, D., Jobst, B., Hugler, M. and Fuchs, G. Malonyl-coenzyme A reductase in the modified 3-hydroxypropionate cycle for autotrophic carbon fixation in archaeal Metallosphaera and Sulfolobus spp. J. Bacteriol. 188 (2006) 8551-8559. [PMID: 17041055]
4. Hugler, M., Menendez, C., Schagger, H. and Fuchs, G. Malonyl-coenzyme A reductase from Chloroflexus aurantiacus, a key enzyme of the 3-hydroxypropionate cycle for autotrophic CO2 fixation. J. Bacteriol. 184 (2002) 2404-2410. [PMID: 11948153]