A SPECIFIC HEPATIC TRANSFER RNA FOR PHOSPHOSERINE
A SPECIFIC HEPATIC TRANSFER RNA FOR PHOSPHOSERINE
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DOI：
10.1073/pnas.67.2.688
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发表时间：
1970-01-01
影响因子：
11.1
通讯作者：
BERNFIELD, MR
中科院分区：
文献类型：
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作者：
MAENPAA, PH;BERNFIELD, MR
大鼠和公鸡肝[~ 3 H]丝氨酰-tRNA在体外用同源合成酶进行碱脱酰后，检测到放射性O-磷酰-L-丝氨酸。核糖核酸酶处理该tRNA产生具有磷酸丝氨酰腺苷性质的化合物。苯甲酰化的DEAE-纤维素层析的丝氨酰-tRNA产生了四个不同的峰，其中只有一个含有磷酸丝氨酸。一个独特的馏分磷酸丝氨酸也被发现对nonacylated tRNA的色谱。在核糖体结合的研究中，这部分非常轻微的聚（U，C），但不与任何已知的丝氨酸三核苷酸密码子。在源自鸡输卵管的氨酰-tRNA依赖性多核糖体系统中观察到[3 H]-丝氨酸大量掺入该tRNA种类的蛋白质中。用同源酶酰化的大肠杆菌酵母丝氨酰-tRNA中未发现磷酸丝氨酸，E.用肝合成酶酰化的coliseryl-tRNA。在不存在tRNA的情况下，反应混合物中没有形成游离的磷酸丝氨酸，这表明磷酸丝氨酸-tRNA是由独特的丝氨酸-tRNA种类的磷酸化产生的。这些结果表明，在大鼠和公鸡肝脏中含有磷酸丝氨酸的离散tRNA Serspecies，并表明这种tRNA参与核糖体多肽的合成。
RadioactiveO-phosphoryl-L-serine was detected after alkaline deacylation of rat and rooster liver [3H]seryl-tRNA acylatedin vitrowith homologous synthetases. Ribonuclease treatment of this tRNA yielded a compound with the properties of phosphoseryl-adenosine. Benzoylated DEAE-cellulose chromatography of seryl-tRNA yielded four distinct peaks, only one of which contained phosphoserine. A unique fraction for phosphoserine was also found on chromatography of nonacylated tRNA. In ribosome binding studies, this fraction responded very slightly with poly(U,C), but not with any of the known serine trinucleotide codons. Substantial incorporation of [3H]-serine into protein from this tRNA species was observed in an aminoacyl-tRNA dependent polysomal system derived from chick oviducts. No phosphoserine was found inEscherichia colior yeast seryl-tRNA acylated with homologous enzymes, nor inE. coliseryl-tRNA acylated with liver synthetase. In the absence of tRNA, free phosphoserine was not formed in reaction mixtures, which suggests that phosphoseryl-tRNA arises by phosphorylation of the unique seryl-tRNA species. These results demonstrate a discrete tRNASerspecies in rat and rooster liver containing phosphoserine and suggest that this tRNA is involved in ribosomal polypeptide synthesis.