Updated annotation (from data): L-2,4-diketo-3-deoxyrhamnonate hydrolase; 2,4-dioxopentanoate hydrolase Rationale: Specifically important in carbon source L-Fucose; carbon source D-Arabinose. SM_b21112 is 58% identical to LRA6, which is L-2,4-diketo-3-deoxyrhamnonate hydrolase (PMID:19187228). This reaction is also proposed to be involved in L-fucose catabolism (PMID:17144652), which explains the phenotype on L-fucose. Its role in D-arabinose catabolism suggests that it also acts on a five-carbon substrate such as 2,4-dioxopentanoate. This protein belongs to the fumarylacetoacetate hydrolase family, which hydrolyses substrates of the form R-CO-CH2-CO-R'. Both keto groups are involved in the catalytic mechanism (Bateman et al 2001) so we propose that 2,4-dioxopentanoate is the intermediate in D-arabinose catabolism. This would be formed from D-arabinoate by two successive dehydratase reactions (see SMa0247 and SM_b21112). Original annotation: bifunctional 2-hydroxyhepta-2,4-diene-1, 7-dioatesomerase/5-carboxymethyl-2-oxo-hex-3-ene-1, 7-dioatedecarboxylase Type 1: Protein-coding gene Located on scaffold NC_003078, + strand, nucleotides 752,976 to 753,821 See nucleotide sequence around SM_b21112 or for all of scaffold NC_003078