Rappu Pekka, Leppihalme Mari, Mäntsälä Pekka
Department of Biochemistry and Food Chemistry, University of Turku, Vatselankatu 2, FI-20014, Turku, Finland.
Curr Microbiol. 2005 Nov;51(5):322-6. doi: 10.1007/s00284-005-0046-6. Epub 2005 Sep 16.
The Bacillus subtilis purine repressor, PurR, regulates many genes involved in purine metabolism. These genes contain a conserved 14-nucleotide inverted repeat (PurBox). Both pur operon and purA, which are regulated by PurR, have this inverted repeat with a 16- or 17-nucleotide spacer, respectively. Mutational studies have earlier shown that PurR binding is dependent on the PurBox of pur operon. In contrast, these studies failed to establish the importance of purA PurBox to PurR binding. To examine this inconsistency, we studied the effects of PurBox mutations both in vivo and in vitro. The data presented here indicate that purA PurBox has a similar role as pur operon PurBox in PurR binding. In addition, our data suggest that the previously proposed classification of the two halves of the Purbox into weak and strong may need to be revised.
枯草芽孢杆菌嘌呤阻遏蛋白PurR调控许多参与嘌呤代谢的基因。这些基因包含一个保守的14个核苷酸的反向重复序列（PurBox）。受PurR调控的嘌呤操纵子和purA基因都有这个反向重复序列，其间隔分别为16或17个核苷酸。早期的突变研究表明，PurR的结合依赖于嘌呤操纵子的PurBox。相比之下，这些研究未能确定purA基因的PurBox对PurR结合的重要性。为了研究这种不一致性，我们在体内和体外研究了PurBox突变的影响。这里给出的数据表明，purA基因的PurBox在PurR结合中与嘌呤操纵子的PurBox具有相似的作用。此外，我们的数据表明，之前提出的将PurBox的两半分为弱和强的分类可能需要修订。
