Paucha E, Mellor A, Harvey R, Smith A E, Hewick R M, Waterfield M D
Proc Natl Acad Sci U S A. 1978 May;75(5):2165-9. doi: 10.1073/pnas.75.5.2165.
Large and small tumor (T)antigens of simian virus 40 were synthesized in vitro with L-cell extracts that had been treated by the method of Palmiter to prevent amino-terminal acetylation of nascent proteins. Partial amino-terminal amino acid sequences of both forms of T-antigen were determined and found to be identical. Methionine residues were located at positions 1 and 14, a lysine residue at position 3, and leucine residues at positions 5, 11, 13,16, 17, and 19. These amino acid sequence data match perfectly the amino acid sequence predicted from a sequence of nucleotides in the E strand of simian virus 40 DNA which begins near the junction between HindII/III fragments A and C at about 0.65 map units. This strongly suggests that the sequence coding for the amino terminus of both proteins is located at this position. Furthermore, the data are consistent with a model for the synthesis of both forms of T-antigen that predicts that (i) small T-antigen is coded for by a sequence of nucleotides from the 5' end of the early region and (ii) large T-antigen is coded for by nucleotide sequences from two noncontiguous regions of simian virus 40 DNA.
用经帕尔米特方法处理过的L细胞提取物在体外合成了猴病毒40的大、小肿瘤（T）抗原，该方法可防止新生蛋白质的氨基末端乙酰化。测定了两种形式T抗原的部分氨基末端氨基酸序列，发现它们是相同的。甲硫氨酸残基位于第1和14位，赖氨酸残基位于第3位，亮氨酸残基位于第5、11、13、16、17和19位。这些氨基酸序列数据与从猴病毒40 DNA的E链核苷酸序列预测的氨基酸序列完全匹配，该序列始于HindII/III片段A和C之间的连接处附近，约在0.65个图谱单位处。这有力地表明，两种蛋白质氨基末端的编码序列位于该位置。此外，这些数据与两种形式T抗原的合成模型一致，该模型预测：（i）小T抗原由早期区域5'端的核苷酸序列编码；（ii）大T抗原由猴病毒40 DNA两个不连续区域的核苷酸序列编码。
