Accepted name: 2-dehydro-3-deoxy-L-rhamnonate dehydrogenase (NAD+)
Reaction: 2-dehydro-3-deoxy-L-rhamnonate + NAD+ = 2,4-didehydro-3-deoxy-L-rhamnonate + NADH + H+
Other name(s): 2-keto-3-deoxy-L-rhamnonate dehydrogenase
Systematic name: 2-dehydro-3-deoxy-L-rhamnonate:NAD+ 4-oxidoreductase
Comments: The enzyme, characterized from the bacteria Sphingomonas sp. SKA58 and Sulfobacillus thermosulfidooxidans, is involved in the non-phosphorylative degradation pathway for L-rhamnose. It does not show any detectable activity with NADP+ or with other aldoses.
1.  Watanabe, S. and Makino, K. Novel modified version of nonphosphorylated sugar metabolism - an alternative L-rhamnose pathway of Sphingomonas sp. FEBS J. 276 (2009) 1554–1567. [PMID: 19187228]
2.  Bae, J., Kim, S.M. and Lee, S.B. Identification and characterization of 2-keto-3-deoxy-L-rhamnonate dehydrogenase belonging to the MDR superfamily from the thermoacidophilic bacterium Sulfobacillus thermosulfidooxidans: implications to L-rhamnose metabolism in archaea. Extremophiles 19 (2015) 469–478. [PMID: 25617114]
[EC created 2016]
Accepted name: 2-keto-3-deoxy-L-rhamnonate aldolase
Reaction: 2-dehydro-3-deoxy-L-rhamnonate = pyruvate + (S)-lactaldehyde
Glossary: 2-dehydro-3-deoxy-L-rhamnonate = 3,6-dideoxy-L-erythro-hex-2-ulosonate
Other name(s): KDR aldolase; 2-dehydro-3-deoxyrhamnonate aldolase; 2-keto-3-deoxy acid sugar aldolase; YfaU; 2-dehydro-3-deoxy-L-rhamnonate (S)-lactaldehyde lyase (pyruvate-forming); 2-dehydro-3-deoxy-L-rhamnonate (R)-lactaldehyde lyase (pyruvate-forming)
Systematic name: 2-dehydro-3-deoxy-L-rhamnonate (S)-lactaldehyde-lyase (pyruvate-forming)
Comments: Requires Mg2+ for activity. The enzyme can also use 2-oxo-3-deoxy-L-mannonate, 2-oxo-3-deoxy-L-lyxonate and 4-hydroxy-2-ketoheptane-1,7-dioate (HKHD) as substrates [2].
1.  Rakus, J.F., Fedorov, A.A., Fedorov, E.V., Glasner, M.E., Hubbard, B.K., Delli, J.D., Babbitt, P.C., Almo, S.C. and Gerlt, J.A. Evolution of enzymatic activities in the enolase superfamily: L-rhamnonate dehydratase. Biochemistry 47 (2008) 9944–9954. [PMID: 18754693]
2.  Rea, D., Hovington, R., Rakus, J.F., Gerlt, J.A., Fulop, V., Bugg, T.D. and Roper, D.I. Crystal structure and functional assignment of YfaU, a metal ion dependent class II aldolase from Escherichia coli K12. Biochemistry 47 (2008) 9955–9965. [PMID: 18754683]
[EC created 2013]
Accepted name: L-rhamnonate dehydratase
Reaction: L-rhamnonate = 2-dehydro-3-deoxy-L-rhamnonate + H2O
Other name(s): L-rhamnonate hydro-lyase
Systematic name: L-rhamnonate hydro-lyase (2-dehydro-3-deoxy-L-rhamnonate-forming)
1.  Rigo, L.U., Maréchal, L.R., Vieira, M.M. and Veiga, L.A. Oxidative pathway for L-rhamnose degradation in Pallularia pullulans. Can. J. Microbiol. 31 (1985) 817–822.
[EC created 1989]