Mung bean nuclease cleavage of a dA + dT-rich sequence or an inverted repeat sequence in supercoiled PM2 DNA depends on ionic environment.
Mung bean nuclease cleavage of a dA + dT-rich sequence or an inverted repeat sequence in supercoiled PM2 DNA depends on ionic environment.
复制标题
绿豆核酸酶对超螺旋 PM2 DNA 中富含 dA dT 的序列或反向重复序列的切割取决于离子环境。
DOI：
10.1093/nar/12.18.7087
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发表时间：
1984
影响因子：
14.9
通讯作者：
Kowalski,D
中科院分区：
文献类型：
--
作者：
Sheflin,LG;Kowalski,D
我们已经确定了在不同的离子环境下，单链特异性绿豆核酸酶在超螺旋PM2 DNA中切割的两个替代位点周围的核苷酸序列。在10 mM Tris-HCl（pH 7.0, 37°C）中，主要位点是一个富含dA+ dt的序列，在0.75个图谱单位处与已知的早期变性区相对应。在135bp的区域内约有30条卵裂。裂解在（dA）n处基本排除。（dT）n （n= 3-7）个序列。这种类型的切割模式以前没有在富含dA+ dt的序列中观察到。当添加0.1 M NaCl时，主要的替代位点出现在500 bp（0.70个图谱单位）以外的连字符反向重复序列中，并且没有映射到早期变性区。在重复序列之间的区域出现了1个主要的和4个次要的裂解，表明识别出一个最多包含一个12bp的茎和10个碱基环的发夹。核酸酶识别富含dA+ dt序列的基础尚不清楚。不同位点的序列和解理模式的差异表明它们的二级结构不同。
We have determined the nucleotide sequences around two alternative sites cleaved in supercoiled PM2 DNA by single-strand-specific mung bean nuclease in different ionic environments. In 10 mM Tris-HCl(pH 7.0, 37°C), the major site is a dA+dT-rich sequence which maps with a known early denaturation region at 0.75 map units. About 30 cleavages occurred in a 135 bp region. Cleavages were largely excluded at (dA)n.(dT)n (n=3–7) sequences. Cleavage patterns of this type have not been previously observed in dA+dT-rich sequences. With the addition of 0.1 M NaCl the major alternative site occurred in a hyphenated inverted repeat sequence 500 bp away (0.70 map units) and did not map to an early denaturation region. One major and 4 minor cleavages occurred in the region between the repeats, suggesting that a hairpin containing at most a 12 bp stem and 10 base loop is recognized. The basis for nuclease recognition of the dA+dT-rich sequence is not clear. The differences in the sequences and cleavage patterns at the alternative sites indicate that their secondary structures differ.