Has dehydrogenase activity against corticosterone (11 beta-hydroxysteroid) and estradiol (17 beta-hydroxysteroid), with higher activity against estradiol. Possesses higher dehydrogenase activity with NADP(+) than NAD(+) regardless of the sterol substrate. May be involved in signal transduction regulated by various sterols. an 11beta-hydroxysteroid + NADP(+) = an 11-oxosteroid + H(+) + NADPH an 11beta-hydroxysteroid + NAD(+) = an 11-oxosteroid + H(+) + NADH corticosterone + NADP(+) = 11-dehydrocorticosterone + H(+) + NADPH corticosterone + NAD(+) = 11-dehydrocorticosterone + H(+) + NADH 17beta-estradiol + NADP(+) = estrone + H(+) + NADPH 17beta-estradiol + NAD(+) = estrone + H(+) + NADH Surface of oil bodies. Exists at a monolayer lipid/water interface. Expressed in seeds (at protein level) (PubMed:11950969, PubMed:9816677). Not expressed in stem, leaf or root (at protein level) (PubMed:9816677). Expressed during seed maturation (PubMed:11950969, PubMed:9816677, PubMed:15331088). Appears in maturing seeds approximately 3 weeks after flowering and thereafter the level is continuously increased till the late stage of seed maturation (at protein level) (PubMed:15331088). Detected in maturing seeds approximately 2 weeks after flowering and expression is maintained at a substantial level thereafter until the late stage of seed maturation (PubMed:11950969). The proline-knob motif may be involved in the targeting to oil bodies. Belongs to the short-chain dehydrogenases/reductases (SDR) family.