InterPro domain: IPR009959

SnoaL adopts a distorted alpha-beta barrel fold [ 1 ]. Structural data together with site-directed mutagenesis experiments have shown that SnoaL has a different mechanism to that of the classical aldolase for catalysing intramolecular aldol condensation [ 2 ].

Polyketides form a diverse group of compounds produced mainly by microorganisms and plants. This family of polyketide synthases includes aklanonic acid methyl ester cyclases, involved in the synthesis of aklavinone, an intermediate in the biosynthetic pathway of clinically important anthracyclines such as daunorubicin and doxorubicin [ 2 , 3 ]. SnoaL belongs to this family; it is involved in nogalamycin biosynthesis [ 4 ].

1. Structure of the polyketide cyclase SnoaL reveals a novel mechanism for enzymatic aldol condensation. EMBO J. 23, 1911-21
2. DnrD cyclase involved in the biosynthesis of doxorubicin: purification and characterization of the recombinant enzyme. Biochemistry 38, 4794-9
3. Analysis of clustered genes encoding both early and late steps in daunomycin biosynthesis by Streptomyces sp. strain C5. J. Bacteriol. 177, 536-43