E. coli ada 변종인 I-27을 MNNG-변이화 방법으로 분리하였다. 이 I-27 변종은 MNNG, MMS와 같은 간단한 알킬화 시약에 대해 증가된 민감성을 나타내었고 MNNG에 대한 적응반응을 유도하지 못하였다. 이 변종은 $O^6$-methylguanine methyltransferase와 3-methyladenine DNA glycosylase II 효소의 활성을 유도하지 못하였다. E. coli K12의 DNA를 제한효소 PstI으로 부분 가수분해한 뒤 pBR322 vector에 접합하여 ada 유전자를 cloning하였다. 재조합 plasmid인 pEMT1은 ada 변종인 I-27이 MNNG에 저항성을 나타내도록 하였으며, 또 유도되지 않은 상태에서도 methyltransferase의 활성을 나타내도록 하였다. pEMT1을 제한효소 Hind III로 가수분해하여 pBR322에 접합시킨 뒤 I-27에 넣어서 subcloning을 하였으며 이 때의 재조합 plasmid인 pEMT2는 Hind III 로 가수분해 한 pEMT1의 3.1 kb 크기의 DNA 조각을 포함하고 있었다.
E. coli ada 변종인 I-27을 MNNG-변이화 방법으로 분리하였다. 이 I-27 변종은 MNNG, MMS와 같은 간단한 알킬화 시약에 대해 증가된 민감성을 나타내었고 MNNG에 대한 적응반응을 유도하지 못하였다. 이 변종은 $O^6$-methylguanine methyltransferase와 3-methyladenine DNA glycosylase II 효소의 활성을 유도하지 못하였다. E. coli K12의 DNA를 제한효소 PstI으로 부분 가수분해한 뒤 pBR322 vector에 접합하여 ada 유전자를 cloning하였다. 재조합 plasmid인 pEMT1은 ada 변종인 I-27이 MNNG에 저항성을 나타내도록 하였으며, 또 유도되지 않은 상태에서도 methyltransferase의 활성을 나타내도록 하였다. pEMT1을 제한효소 Hind III로 가수분해하여 pBR322에 접합시킨 뒤 I-27에 넣어서 subcloning을 하였으며 이 때의 재조합 plasmid인 pEMT2는 Hind III 로 가수분해 한 pEMT1의 3.1 kb 크기의 DNA 조각을 포함하고 있었다.
An Escherichia coli ada mutant, I-27, was isolated by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) treatment. This mutant showed increased sensitivity to simple alkylating agents such as MNNG and methyl-methanesulphonate (MMS) and was unable to induce the adaptive response to MNNG. The I-27 was defec...
An Escherichia coli ada mutant, I-27, was isolated by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) treatment. This mutant showed increased sensitivity to simple alkylating agents such as MNNG and methyl-methanesulphonate (MMS) and was unable to induce the adaptive response to MNNG. The I-27 was defective in inducing activities of $O^6$-methylguanine methyltransferase and 3-methyladenine DNA glycosylase II. The $ada^+$ gene was cloned from wild type E. Coli K12 by ligating bacterial DNA partially digested with PstI into pBR322. The recombinant plasmid, obtained above, gave MNNG resistance to ada mutant, I-27, and resulted in the constitutive synthesis of methyltransferase. Further subcloning of pEMT1 was achieved by ligating a Hind III digest of pEMT1 into pBR322 and transforming it into the 1-27, an ada mutant. The resultant recombinant plasmid, pEMT2, contained a 3.1 kb Hind III fragment of the pEMT1 DNA.
An Escherichia coli ada mutant, I-27, was isolated by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) treatment. This mutant showed increased sensitivity to simple alkylating agents such as MNNG and methyl-methanesulphonate (MMS) and was unable to induce the adaptive response to MNNG. The I-27 was defective in inducing activities of $O^6$-methylguanine methyltransferase and 3-methyladenine DNA glycosylase II. The $ada^+$ gene was cloned from wild type E. Coli K12 by ligating bacterial DNA partially digested with PstI into pBR322. The recombinant plasmid, obtained above, gave MNNG resistance to ada mutant, I-27, and resulted in the constitutive synthesis of methyltransferase. Further subcloning of pEMT1 was achieved by ligating a Hind III digest of pEMT1 into pBR322 and transforming it into the 1-27, an ada mutant. The resultant recombinant plasmid, pEMT2, contained a 3.1 kb Hind III fragment of the pEMT1 DNA.
※ AI-Helper는 부적절한 답변을 할 수 있습니다.