Staphylococcus aureus primase has higher initiation specificity, interacts with single-stranded DNA stronger, but is less stimulated by its helicase than Escherichia coli primase
Staphylococcus aureus primase has higher initiation specificity, interacts with single-stranded DNA stronger, but is less stimulated by its helicase than Escherichia coli primase
复制标题
DOI：
10.1111/j.1365-2958.2008.06255.x
复制
发表时间：
2008-06-01
影响因子：
3.6
通讯作者：
Griep, Mark A.
中科院分区：
文献类型：
--
作者：
Koepsell, Scott A.;Larson, Marilynn A.;Griep, Mark A.
对来自模式生物如大肠杆菌、噬菌体T7和噬菌体T4的引发酶的研究已经证明了引发酶功能的本质，即产生从头RNA聚合物以引发DNA聚合酶。然而，对其他真细菌的引发酶的功能知之甚少。它们总体上较低的一级序列同源性可能导致功能差异。为了帮助理解哪些引发酶功能是保守的，我们详细比较了致病性革兰氏阳性菌金黄色葡萄球菌和大肠杆菌的引发酶及其复制伴侣解旋酶。coli引发酶和解旋酶。保守的性质是引物起始和延伸，包括缓慢的动力学，低保真度和差的糖特异性。显著差异包括S。金黄色葡萄球菌引发酶对其模板的动力学亲和力比E.大肠杆菌引发酶在相同条件下的反应。与E.大肠杆菌引发酶。两种引物最显著的差异是S.金黄色葡萄球菌解旋酶的刺激并没有使S.金黄色葡萄球菌引发酶起始特异性，这具有重要的生物学意义。
The study of primases from model organisms such as Escherichia coli, phage T7 and phage T4 has demonstrated the essential nature of primase function, which is to generate de novo RNA polymers to prime DNA polymerase. However, little is known about the function of primases from other eubacteria. Their overall low primary sequence homology may result in functional differences. To help understand which primase functions were conserved, primase and its replication partner helicase from the pathogenic Gram-positive bacteria Staphylococcus aureus were compared in detail with that of E. coli primase and helicase. The conserved properties were to primer initiation and elongation and included slow kinetics, low fidelity and poor sugar specificity. The significant differences included S. aureus primase having sixfold higher kinetic affinity for its template than E. coli primase under equivalent conditions. This naturally higher activity was balanced by its fourfold lower stimulation by its replication fork helicase compared with E. coli primase. The most significant difference between the two primases was that S. aureus helicase stimulation did not broaden the S. aureus primase initiation specificity, which has important biological implications.