Watanabe S, Chou J Y
Human Genetics Branch, National Institute of Child Health and Human Development, Bethesda, Maryland 20892.
Biochem Biophys Res Commun. 1988 Apr 29;152(2):762-8. doi: 10.1016/s0006-291x(88)80103-7.
The amino acid sequence of human pregnancy-specific beta 1-glycoprotein (PS beta G) as deduced from the cDNA sequence contains two repeated protein domains (1a and 2a) of 93 amino acids each. PS beta G shows strong homology to human carcinoembryonic antigen (CEA) at both nucleotide and amino acid levels. CEA contains eight domains including a N-terminal domain, three repeated domains (I, II, and III), each containing two subdomains (A and B), and a hydrophobic carboxyl-terminal domain. PS beta G contains a CEA-like N-terminal domain, two repeated domains similar to the A subdomains of CEA which is followed by a domain (1b) similar to the B subdomains of CEA, but lacks a hydrophobic carboxyl-terminal domain. The positions of the cysteine residues in each domain also are conserved, indicating that PS beta G and CEA are two members of the same gene family.
从cDNA序列推导得出的人妊娠特异性β1-糖蛋白（PSβG）的氨基酸序列包含两个重复的蛋白质结构域（1a和2a），每个结构域有93个氨基酸。PSβG在核苷酸和氨基酸水平上均与人癌胚抗原（CEA）有很强的同源性。CEA包含八个结构域，包括一个N端结构域、三个重复结构域（I、II和III），每个重复结构域包含两个亚结构域（A和B），以及一个疏水的羧基末端结构域。PSβG包含一个类似CEA的N端结构域、两个与CEA的A亚结构域相似的重复结构域，其后是一个与CEA的B亚结构域相似的结构域（1b），但缺少疏水的羧基末端结构域。每个结构域中半胱氨酸残基的位置也是保守的，这表明PSβG和CEA是同一基因家族的两个成员。
