AMINO-ACID REPLACEMENTS IN PROTEINS S5 AND S12 OF 2 ESCHERICHIA-COLI REVERTANTS FROM STREPTOMYCIN DEPENDENCE TO INDEPENDENCE
AMINO-ACID REPLACEMENTS IN PROTEINS S5 AND S12 OF 2 ESCHERICHIA-COLI REVERTANTS FROM STREPTOMYCIN DEPENDENCE TO INDEPENDENCE
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DOI：
10.1007/bf00267779
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发表时间：
1973-01-01
期刊：
影响因子：
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通讯作者：
WITTMANN, HG
中科院分区：
文献类型：
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作者：
ITOH, T;WITTMANN, HG
从两个菌株中分离出核糖体。从链霉素依赖到独立的大肠埃希菌，n660和d1023。亚基分离后，从核糖体30S亚基中提取蛋白质，经CM-纤维素柱层析和凝胶过滤分离。用胰酶消化两株突变体的S5和S12蛋白，用柱层析法和纸层析法分离得到全部多肽。将4个突变蛋白的多肽与野生型A19的相应多肽进行了氨基酸组成比较。对不同的氨基酸序列进行了测定，发现N660蛋白S5的T2肽中的甘氨酸被精氨酸取代，同一突变株S12的T15肽中的甘氨酸被天冬氨酸取代。在另一个突变体d1023中，S5蛋白的T2肽中的精氨酸被亮氨酸取代，而S12蛋白的T10肽中的精氨酸被丝氨酸取代。除了上述与单核苷酸变化相适应的氨基酸替换外，从菌株A19和突变株d1023分离的蛋白S12的多肽T15之间也有相当大的差异。本文的结果与E.Coli.
Ribosomes were isolated from twoE. colirevertants from streptomycin dependence to independence, N660 and d1023. After separation of subunits, proteins were extracted from ribosomal 30S subunits and separated by CM-cellulose column chromatography and gel filtration. Pure S5 and S12 proteins of the two mutants were digested with trypsin and all resulting peptides were isolated by column and paper chromatography. The amino acid compositions of the peptides from the four mutant proteins were compared with the corresponding peptides of the wild type strain A19. The amino acid sequences of non-identical peptides were determined.The following amino acid replacements were found: Glycine by arginine in peptide T2 of protein S5 from mutant N660 and glycine by aspartic acid in peptide T15 of protein S12 from the same mutant. In the other mutant, d1023, arginine in peptide T2 of protein S5 was replaced by leucine and furthermore arginine by serine in peptide T10 of protein S12. Besides the single amino acid replacements mentioned above which are compatible with alterations of single nucleotides, a rather drastic difference between peptides T15 of proteins S12 isolated from strain A19 and mutant d1023 has been detected.The results presented in this paper are compared with amino acid replacements in proteins S5 and S12 from other ribosomal mutants ofE. coli.