| Literature References | 1. NTAMBI, J.M., BUHROW, S.A., KAESTNER, K.H., CHRISTY, R.J., SIBLEY, E.,
KELLY, T.J. AND LANE, M.D.
Differentiation-induced gene expression in 3T3-L1 preadipocytes.
Characterization of a differentially expressed gene encoding stearoyl-CoA
desturase.
J.BIOL.CHEM. 263 17291-17300 (1988).
2. STUKEY, J.E., MCDONOUGH, V.M. AND MARTIN, C.E.
The OLE1 gene of Saccharomyces cerevisiae encodes the delta 9 fatty acid
desaturase and can be functionally replaced by the rat stearoyl-CoA
desaturase gene,
J.BIOL.CHEM. 265 20144-20149 (1990).
3. THIEDE, M.A., OZOLS, J. AND STRITTMATTER, P.
Construction and sequence of cDNA for rat liver stearoyl coenzyme A
desaturase.
J.BIOL.CHEM. 261 13230-13235 (1986).
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| Documentation | Fatty acid desaturases are enzymes that insert double bonds in the delta
position of saturated fatty acids. There are 2 distinct enzyme families:
the first contains stearoyl-CoA desaturase (SCD); the second includes plant
stearoyl-acyl-carrier protein and cyanobacteria desA protein. SCD is an
essential enzyme in the synthesis of unsaturated fatty acids [1]: in
association with cytochrome b5 and NADP-dependent cytochrome b5 reductase,
it constitutes part of a microsomal membrane-bound 3-component system in
animals and fungi [1]. SCD contains 4 putative transmembrane (TM) regions
that anchor it in the microsomal membrane.
The enzyme uses oxygen and electrons from reduced cytochrome b5 [2,3] to
catalyse the insertion of a double bond between carbons 9 and 10 of a
spectrum of fatty acids [1-3]. The preferred substrates of SCD are
palmitoyl-CoA and stearoyl-CoA, which are converted to palmitoleic (16:1)
and oleic (18:1) acids respectively [1,3]. These unsaturated molecules
are the major storage form of fatty acids (as triacylglycerols) in
adipocytes [1].
FACDDSATRASE is a 7-element fingerprint that provides a signature for
fatty acid desaturase family 1. The fingerprint was derived from an initial
alignment of 4 sequences: motifs 1, 2, 5 and 6 were drawn from the 4
putative TM regions, and motif 7 includes the region encoded by PROSITE
pattern FATTY_ACID_DESATUR_1 (PS00476), which spans a C-terminal aromatic/
His-rich domain. Two iterations on OWL25.1 were required to reach
convergence, at which point a true set comprising 7 sequences was
identified.
An update on SPTR37_9f identified a true set of 19 sequences, and 12
partial matches.
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