摘要
硒蛋白是微量元素硒以硒代半胱氯酸(SeC)形式进入多肽链的蛋白质。SeC的遗传密码是UGA。在原核细胞中,4种基因产物SELA、SELB、SELC和SELD参与了硒蛋白的合成过程。真核生物硒蛋白mRNA3’-UTR的硒代半胱氨酸插入序列(SECIS)是真核细胞UGA密码编码SeC的顺式作用元件。动物的硒营养状态不影响硒蛋白基因的转录,但影响硒蛋白mRNA的稳定性。饲料硒水平与含硒酶活性呈正相关。
Selenoproteins are this kind of protein where selenium presents as selenocysteine. It is known that specific insertion of selenocysteine into protein is directed by the UGA codon.For the prokaryotic cells, 4 kinds of gene(sel A、sel B、sel C and sel D)products participate in the synthesis of selenoproteins. In eukaryotes, co- translational insertion of selenocysteine into selenoproteins necessitates the participation of the selenocysteine insertion sequence(SECTS), a cis - acting element lying in the 3' - UTR of selenoproteins mRNAs. In animal body, selenium does not affect the transcription of selenoprotein genes, it affects the stability of selenoproteins mRNAs. The level of selenium in feeds is positive correlation with the activity of selenoenzymes.
出处
《动物营养学报》
CAS
CSCD
2003年第3期12-17,共6页
CHINESE JOURNAL OF ANIMAL NUTRITION
