Sterol methyltransferases

Arnqvist, L., Dutta, P. C., Jonsson, L., Sitbon, F. (2003). Reduction of cholesterol and glycoalkaloid levels in transgenic potato plants by overexpression of a type 1 sterol methyltransferase cDNA. Plant Physiol., 131, 1792-1799. 

GREBENOK, R. J., GALBRAITH, D. W., DELLAPENNA, D, Characterization of Zea mays endosperm C-24 sterol methyltransferase One of two types of sterol methyltransferase in higher plants., Plant Mol.Biol., 1997,34, 891-896. 

SCHAEFFER, A., BRONNER, R, BENVENISTE, P., SCHALLER, H., The ratio of campesterol to sitosterol that modulates growth in Arabidopsis is controlled by STEROL METHYLTRANSFERASE 2 1., Plant J 2001,25, 605-615. 

Bouvier-Nave, R, Husselstein, T. and Benveniste, R (1998) Two families of sterol methyltransferases are involved in the first and the second methylation steps of plant sterol biosynthesis. Eur.. Biochem., 256,88-96. 

Fig. 9. Methylation at C24 of the C24,25-unsaturated side chain of various sterols. R represents the ring system of the appropriate sterol. A -Sterol methyltransferase has been purified from the microsomal fraction of yeast grown aerobically at the expense of glucose. When ethanol serves as the carbon source, the enzyme is found in the mitochondria. If mitochondrial development is represssed by anae-robiosis in the presence of 10% glucose, the enzyme is present in the promitochondrial fraction.

Diener AC, Li HX, Zhou WX, Whoriskey WJ, Nes WD, Fink GR (2000) Sterol methyltransferase 1 controls the level of cholesterol in plants. Plant Cell 12 853-870... 

Ishida K, Rodrigues JC, Ribeiro MD et al (2009) Growth inhibition and ultrastructural alterations induced by Delta24(25)-sterol methyltransferase inhibitors in Candida spp. isolates, including nonalbicans organisms. BMC Microbiol 9 74... 

There is little evidence for the participation of cofactors or other activators in transmethylation reactions. An occasional methyltransferase has been found to be stabilized by mercaptoethanol or other sulfhydryl compounds and to be inhibited by p-chloromercuribenzoate (Mann and Mudd, 1963). A purified yeast sterol methyltransferase requires gluta-... 

A.C. Oehlschlager, R.H. Angus, A.M. Pierce, H.D. Pierce and R. Srinivasan, Azasterol inhibition of sterol methyltransferase in Saccharomyces cerevisiae. 

Although ERG6 appears to participate in multiple activities, erg6 mutants are not lethal. The sterol methyltransferase is such a metabolically expensive reaction, it is most likely that the retention of such a reaction has evolutionary selective advantages to the yeast. 

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