Reaction: 3-hydroxypropanoate + NADP+ = malonate semialdehyde + NADPH + H+
For diagram of reaction click here (another example, another example).
Systematic name: 3-hydroxypropanoate:NADP+ oxidoreductase
Comments: Catalyses the reduction of malonate semialdehyde to 3-hydroxypropanoate, 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 archaea, respectively [1,2]. The enzyme from Chloroflexus aurantiacus is bifunctional, and also catalyses the upstream reaction in the pathway, EC 1.2.1.75 [3]. Different from EC 1.1.1.59 [3-hydroxypropionate dehydrogenase (NAD+)] by cofactor preference.
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. 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]