2 TYPE-I RESTRICTION ENZYMES FROM SALMONELLA SPECIES - PURIFICATION AND DNA RECOGNITION SEQUENCES
2 TYPE-I RESTRICTION ENZYMES FROM SALMONELLA SPECIES - PURIFICATION AND DNA RECOGNITION SEQUENCES
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DOI：
10.1016/0022-2836(85)90243-8
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发表时间：
1985-01-01
影响因子：
5.6
通讯作者：
BICKLE, TA
中科院分区：
文献类型：
--
作者：
NAGARAJA, V;SHEPHERD, JCW;BICKLE, TA
对S.鼠伤寒沙门氏菌和S.波茨坦，并测定它们识别的DNA序列。这些序列类似于先前确定的I型酶的序列。EcoB、EcoK和EcoA，因为序列的特定部分被非特异性序列的间隔区分成2个结构域，所述间隔区对于每种酶具有固定长度。从先前确定的序列中可以看出两个主要差异。这两个新序列都是简并的，其中一个SB具有1个三核苷酸和1个五核苷酸特异性结构域，而不是所有其他酶的三核苷酸和四核苷酸结构域。识别序列的唯一保守特征是在修饰反应中被甲基化的腺苷残基。对于所有的酶来说，它们都相隔10或11个碱基对，DNA的每条链上都有1个碱基对。这表明酶沿着双螺旋的沿着1面与DNA结合，在2个连续的大沟中产生蛋白质-DNA相互作用，其中大部分非特异性间隔序列在插入的小沟中。
The type I restriction enzymes SB and SP from S. typhimurium and S. potsdam, respectively, were purified and the DNA sequences that they recognize were determined. These sequences resemble those previously determined for the type I enzymes. EcoB, EcoK and EcoA, in that the specific part of the sequence is divided into 2 domains by a spacer of non-specific sequence that has a fixed length for each enzyme. Two main differences from the previously determined sequences are seen. Both of the new sequences are degenerate and 1 of them, SB, has 1 trinucleotide and 1 pentanucleotide-specific domain rather than the trinucleotide and tetranucleotide domains seen for all of the other enzymes. The only conserved features of the recognition sequences are the adenosyl residues that are methylated in the modification reaction. For all of the enzymes these are situated 10 or 11 base-pairs apart, 1 on each strand of the DNA. This suggests that the enzymes bind to DNA along 1 face of the double helix making protein-DNA interaction in 2 successive major grooves with most of the non-specific spacer sequence in the intervening minor groove.