Baker M E
Department of Medicine, University of California, San Diego, La Jolla 92093.
Mol Endocrinol. 1989 May;3(5):881-4. doi: 10.1210/mend-3-5-881.
The amino acid sequence of human placental 17 beta-hydroxysteroid dehydrogenase (17 beta-OH-steroid dehydrogenase) was found to be similar to that of the NodG protein of Rhizobium meliloti. The computer-based comparison score is 11.5 SD higher than that obtained with 2500 comparisons of randomized sequences of these proteins. The probability of getting such a score by chance is 6 x 10(-31). 17 beta-OH-steroid dehydrogenase is also similar to Klebsiella aerogenes ribitol dehydrogenase and Escherichia coli glucitol-6-phosphate dehydrogenase. We propose that the steroid recognition site on 17 beta-OH-steroid dehydrogenase evolved from an ancestral recognition site for polyols such as ribitol and glucitol-6-phosphate.
发现人胎盘17β-羟基类固醇脱氢酶（17β-OH-类固醇脱氢酶）的氨基酸序列与苜蓿根瘤菌的NodG蛋白的氨基酸序列相似。基于计算机的比较得分比这些蛋白质随机序列的2500次比较所获得的得分高11.5个标准差。偶然获得这样一个得分的概率为6×10⁻³¹。17β-OH-类固醇脱氢酶也与产气克雷伯菌核糖醇脱氢酶和大肠杆菌葡萄糖醇-6-磷酸脱氢酶相似。我们提出，17β-OH-类固醇脱氢酶上的类固醇识别位点是从对诸如核糖醇和葡萄糖醇-6-磷酸等多元醇的祖先识别位点进化而来的。
