StpA protein from Escherichia coli condenses supercoiled DNA in preference to linear DNA and protects it from digestion by DNase I and EcoKI.
StpA protein from Escherichia coli condenses supercoiled DNA in preference to linear DNA and protects it from digestion by DNase I and EcoKI.
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DOI：
10.1093/nar/gki951
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发表时间：
2005
影响因子：
14.9
通讯作者：
Dryden DT
中科院分区：
文献类型：
--
作者：
Keatch SA;Leonard PG;Ladbury JE;Dryden DT
大肠杆菌的核相关蛋白StpA非特异性地与双链DNA （dsDNA）结合，并明显地在邻近的DNA片段之间形成桥梁。这种蛋白质在DNA上的涂层可能会阻碍核酸酶的作用。我们证明了StpA结合阻碍了非特异性内切酶DNase I和位点特异性I型限制性内切酶EcoKI对dsDNA的切割。每250-300 bp的超螺旋DNA大约需要1个StpA分子，每60-100 bp的线性DNA大约需要1个StpA分子才能对核酸酶产生强烈的抑制作用。这些结果支持StpA作为一种核结构蛋白的作用，它将DNA片段结合在一起。EcoKI在ATP水解驱动的广泛DNA易位后，在远离其初始目标序列的位置切割DNA，对其的抑制表明，即使在DNA损伤期间，当染色体上出现潜在致命的未修饰的目标位点时，这些酶也无法在染色体DNA上起作用。这支持了核相关蛋白在细胞应激期间限制缓解中的作用。
The nucleoid-associated protein, StpA, of Escherichia coli binds non-specifically to double-stranded DNA (dsDNA) and apparently forms bridges between adjacent segments of the DNA. Such a coating of protein on the DNA would be expected to hinder the action of nucleases. We demonstrate that StpA binding hinders dsDNA cleavage by both the non-specific endonuclease, DNase I, and by the site-specific type I restriction endonuclease, EcoKI. It requires approximately one StpA molecule per 250–300 bp of supercoiled DNA and approximately one StpA molecule per 60–100 bp on linear DNA for strong inhibition of the nucleases. These results support the role of StpA as a nucleoid-structuring protein which binds DNA segments together. The inhibition of EcoKI, which cleaves DNA at a site remote from its initial target sequence after extensive DNA translocation driven by ATP hydrolysis, suggests that these enzymes would be unable to function on chromosomal DNA even during times of DNA damage when potentially lethal, unmodified target sites occur on the chromosome. This supports a role for nucleoid-associated proteins in restriction alleviation during times of cell stress.
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影响因子：
14.9
作者：
Dame, RT;Wyman, C;Goosen, N
通讯作者：
Goosen, N
影响因子：
3.9
作者：
MCGOVERN, V;HIGGINS, NP;JAWORSKI, A
通讯作者：
JAWORSKI, A
影响因子：
2.4
作者：
MARKO, JF;SIGGIA, ED
通讯作者：
SIGGIA, ED
影响因子：
2.1
作者：
Azam, TA;Hiraga, S;Ishihama, A
通讯作者：
Ishihama, A
影响因子：
3.2
作者：
Dame, RT;Luijsterburg, MS;Wuite, GJL
通讯作者：
Wuite, GJL