Regulation of DNA replication in B.subtilis by YabA

描述（由申请人提供）：用于控制革兰氏阳性细菌复制起始时间和频率的机制尚不清楚。YabA是枯草芽孢杆菌复制起始的负调节因子，在其他革兰氏阳性菌中是保守的。YabA实现其调控功能的机制尚不清楚。我发现YabA与染色体复制起源（oriC）相关，并在复制解旋酶装载后的一个步骤中被运送到那里。我提出了一系列的实验来确定YabA与oriC关联的必要因素。我还建议进行实验，以确定YabA的亚细胞位置及其与染色体的关联是否在复制周期中发生变化。这些实验应该为YabA在抑制复制起始中的作用时间提供见解。最后，我提出了几个体内和体外实验来确定YabA抑制复制起始的机制。

DESCRIPTION (provided by applicant): The mechanism(s) used to control the timing and frequency of replication initiation in Gram positive bacteria are unknown. YabA is a negative regulator of replication initiation in B. subtilis, and is conserved in other Gram positive bacteria. The mechanism by which YabA carries out its regulatory function is not yet understood. I found that YabA associates with the chromosomal origin of replication (oriC), and is delivered there at a step following the loading of the replicative helicase. I propose a series of experiments to identify the factor(s) necessary for association of YabA with oriC. I also propose experiments to determine if the subcellular location of YabA and its association with the chromosome changes during the replication cycle. These experiments should provide insights into the timing of YabA's function in inhibition of replication initiation. Finally, I propose several in vivo and in vitro experiments to determine the mechanism of inhibition of replication initiation by YabA. PUBLIC HEALTH RELEVANCE: Regulation of DNA replication is critical for survival and growth, and is generally achieved by controlling the timing and frequency of replication initiation. The mechanisms behind this kind of control remain elusive in a large subset of bacteria known as Gram-positives, a subgroup of which contribute to pathogenesis and human disease. The goal of this project is to study one of the mechanisms behind DNA replication control, and the results of this proposal could contribute to better understanding of these processes, as well as provide general insights into replication control in pathogenic bacteria.