Kobryn Kerri, Chaconas George
Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta T2N 4N1, Canada.
Mol Cell. 2005 Mar 18;17(6):783-91. doi: 10.1016/j.molcel.2005.02.025.
Spirochetes of the genus Borrelia include the causative agents of Lyme disease and relapsing fever. These bacteria have a highly segmented genome where most replicons are linear molecules terminated by covalently closed hairpin telomeres. Moreover, these genomes appear to be in a state of flux with extensive and ongoing DNA rearrangements by unknown mechanisms. The B. burgdorferi telomere resolvase ResT generates the hairpin telomeres from replication intermediates in a reaction with mechanistic similarities to that catalyzed by type IB topoisomerases and tyrosine recombinases. We report here the unexpected ability of ResT to catalyze the fusion of hairpin telomeres in a reversal of the telomere resolution reaction. We propose that stabilized ResT-mediated telomere fusions are an underlying force for maintaining the B. burgdorferi genome in a state of flux.
疏螺旋体属的螺旋体包括莱姆病和回归热的病原体。这些细菌具有高度分段的基因组，其中大多数复制子是由共价封闭的发夹端粒终止的线性分子。此外，这些基因组似乎处于动态变化状态，通过未知机制进行广泛且持续的DNA重排。伯氏疏螺旋体端粒解离酶ResT在与IB型拓扑异构酶和酪氨酸重组酶催化的反应具有相似机制的反应中，从复制中间体产生发夹端粒。我们在此报告了ResT具有意想不到的能力，即在端粒解离反应的逆转中催化发夹端粒的融合。我们提出，稳定的ResT介导的端粒融合是使伯氏疏螺旋体基因组保持动态变化状态的潜在力量。
