IUBMB Enzyme Nomenclature


Accepted name: sphingolipid C4-monooxygenase

Reaction: a dihydroceramide + 2 ferrocytochrome b5 + O2 + 2 H+ = a (4R)-4-hydroxysphinganine ceramide + 2 ferricytochrome b5 + H2O

Other name(s): sphinganine C4-monooxygenase; sphingolipid C4-hydroxylase; SUR2 (gene name); SBH1 (gene name); SBH2 (gene name); DEGS2 (gene name)

Systematic name: dihydroceramide,ferrocytochrome b5:oxygen oxidoreductase (C4-hydroxylating)

Comments: The enzyme, which belongs to the familiy of endoplasmic reticular cytochrome b5-dependent enzymes, is involved in the biosynthesis of sphingolipids in eukaryotes. Some enzymes are bifunctional and also catalyse EC, sphingolipid 4-desaturase [4].

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:


1. Haak, D., Gable, K., Beeler, T. and Dunn, T. Hydroxylation of Saccharomyces cerevisiae ceramides requires Sur2p and Scs7p. J. Biol. Chem. 272 (1997) 29704-29710. [PMID: 9368039]

2. Grilley, M.M., Stock, S.D., Dickson, R.C., Lester, R.L. and Takemoto, J.Y. Syringomycin action gene SYR2 is essential for sphingolipid 4-hydroxylation in Saccharomyces cerevisiae. J. Biol. Chem. 273 (1998) 11062-11068. [PMID: 9556590]

3. Sperling, P., Ternes, P., Moll, H., Franke, S., Zähringer, U. and Heinz, E. Functional characterization of sphingolipid C4-hydroxylase genes from Arabidopsis thaliana. FEBS Lett. 494 (2001) 90-94. [PMID: 11297741]

4. Ternes, P., Franke, S., Zähringer, U., Sperling, P. and Heinz, E. Identification and characterization of a sphingolipid Δ4-desaturase family. J. Biol. Chem. 277 (2002) 25512-25518. [PMID: 11937514]

5. Mizutani, Y., Kihara, A. and Igarashi, Y. Identification of the human sphingolipid C4-hydroxylase, hDES2, and its up-regulation during keratinocyte differentiation. FEBS Lett. 563 (2004) 93-97. [PMID: 15063729]

[EC created 2012 as EC, transferred 2015 to EC]

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