Marks A R, McIntyre J O, Duncan T M, Erdjument-Bromage H, Tempst P, Fleischer S
Brookdale Center for Molecular Biology, Mount Sinai School of Medicine, New York, New York 10029.
J Biol Chem. 1992 Aug 5;267(22):15459-63.
The complete amino acid sequence of human heart (R)-3-hydroxybutyrate dehydrogenase (EC 1.1.1.30) has been deduced from the nucleotide sequence of cDNA clones. This mitochondrial enzyme has an absolute and specific requirement of phosphatidylcholine for enzymic activity (allosteric activator) and is an important prototype of lipid-requiring enzymes. Despite extensive studies, the primary sequence has not been available and is now reported. The mature form of the enzyme consists of 297 amino acids (predicted M(r) of 33,117), does not appear to contain any transmembrane helices, and is homologous with the family of short-chain alcohol dehydrogenases (SC-ADH) (Persson, B., Krook, M., and Jörnvall, H. (1991) Eur. J. Biochem. 200, 537-543) (30% residue identity with human 17 beta-hydroxysteroid dehydrogenase). The first two-thirds of the enzyme includes both putative coenzyme binding and active site conserved residues and exhibits a predicted secondary structure motif (alternating alpha-helices and beta-sheet) characteristic of SC-ADH. Bovine heart peptide sequences (174 residues in nine sequences determined by microsequencing) have extensive homology (89% identical residues) with the deduced human heart sequence. The C-terminal third (Asn-194 to Arg-297) shows little sequence homology with the SC-ADH and likely contains elements that determine the substrate specificity for the enzyme including the phospholipid (phosphatidylcholine) binding site(s). Northern blot analysis identifies a 1.3-kilobase mRNA encoding the enzyme in heart tissue.
已从互补DNA（cDNA）克隆的核苷酸序列推导得到人心肌（R）-3-羟基丁酸脱氢酶（EC 1.1.1.30）的完整氨基酸序列。这种线粒体酶的酶活性（变构激活剂）对磷脂酰胆碱有绝对且特异的需求，是一种需要脂质的酶的重要原型。尽管进行了广泛研究，但该酶的一级序列一直未知，现予以报道。该酶的成熟形式由297个氨基酸组成（预测分子量为33,117），似乎不包含任何跨膜螺旋，并且与短链醇脱氢酶（SC-ADH）家族同源（佩尔松，B.，克鲁克，M.，和约恩瓦尔，H.（1991年）《欧洲生物化学杂志》200，537 - 543）（与人17β-羟基类固醇脱氢酶有30%的残基同一性）。该酶的前三分之二包含假定的辅酶结合位点和活性位点保守残基，并呈现出预测的SC-ADH特有的二级结构基序（交替的α-螺旋和β-折叠）。牛心肌肽序列（通过微量测序确定的9个序列中的174个残基）与推导得到的人心肌序列有广泛的同源性（89%的相同残基）。C端的三分之一（天冬酰胺-194至精氨酸-297）与SC-ADH的序列同源性较低，可能包含决定该酶底物特异性的元件，包括磷脂（磷脂酰胆碱）结合位点。Northern印迹分析在心脏组织中鉴定出一个编码该酶的1.3千碱基的信使核糖核酸（mRNA）。
