Role of arginine-43 and arginine-69 of the Hin recombinase catalytic domain in the binding of Hin to the hix DNA recombination sites
Role of arginine-43 and arginine-69 of the Hin recombinase catalytic domain in the binding of Hin to the hix DNA recombination sites
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DOI：
10.1046/j.1365-2958.1997.4141789.x
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发表时间：
1997-06-01
影响因子：
3.6
通讯作者：
Hughes, KT
中科院分区：
文献类型：
--
作者：
Adams, CW;Nanassy, O;Hughes, KT
Hin重组酶介导沙门氏菌染色体的区段在两个侧翼26 bp hix DNA重组位点之间的位点特异性倒位。鉴定了Hin重组酶催化结构域的两个氨基酸残基R43和R69中的突变，其可以补偿由于消除hix重组位点内的某些大沟和小沟接触而导致的结合损失。除了一个例外，与野生型Hin不同，R43和R69突变体也能够结合hix序列，其中在该位点的中心添加了额外的4 bp。纯化的Hin突变体R43 H和R69 C在体外具有部分切割和反转活性，而突变体R43 L、R43 C、R69 S和R69 P没有检测到切割和反转活性。这些数据支持催化结构域在DNA结合特异性中起作用的模型，并且表明位置43和69处的精氨酸残基用于在重组反应中的步骤中将Hin重组酶定位在DNA上，所述步骤发生在DNA切割时和/或之前。
The Hin recombinase mediates the site-specific inversion of a segment of the Salmonella chromosome between two flanking 26 bp hix DNA recombination sites. Mutations in two amino acid residues, R43 and R69 of the catalytic domain of the Hin recombinase, were identified that can compensate for loss of binding resulting from elimination of certain major and minor groove contacts within the hix recombination sites. With one exception, the R43 and R69 mutants were also able to bind a hix sequence with an additional 4 bp added to the centre of the site, unlike wild-type Hin. Purified Hin mutants R43H and R69C had both partial cleavage and inversion activities in vitro while mutants R43L, R43C, R69S, and R69P had no detectable cleavage and inversion activities. These data support a model in which the catalytic domain plays a role in DNA-binding specificity, and suggest that the arginine residues at positions 43 and 69 function to position the Hin recombinase on the DNA for a step in the recombination reaction which occurs either at and/or prior to DNA cleavage.