Unprecedented large inverted repeats at the replication terminus of circular bacterial chromosomes suggest a novel mode of chromosome rescue.
Unprecedented large inverted repeats at the replication terminus of circular bacterial chromosomes suggest a novel mode of chromosome rescue.
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DOI：
10.1038/srep44331
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发表时间：
2017-03-10
影响因子：
4.6
通讯作者：
van de Guchte M
中科院分区：
文献类型：
--
作者：
El Kafsi H;Loux V;Mariadassou M;Blin C;Chiapello H;Abraham AL;Maguin E;van de Guchte M
第一个德布鲁克氏乳杆菌。保加利亚菌基因组序列揭示了在复制末端存在一个非常大的反向重复序列（IR），这种DNA序列排列迄今为止在非操作的环状细菌染色体中似乎是不可想象的。这一有趣的观察结果促使我们调查是否可以在其他细菌中发现类似的IRs。在所有5株L. delbrueckii ssp的复制末端都发现了大小在38 ~ 76 kbp之间的IRs。保加利亚的染色体分析，但没有在1373其他染色体。它们代表了在环状细菌基因组中检测到的第一个自然发生的非常大的IRs。5株L. delbrueckii ssp中保加利亚乳杆菌复制末端区与无IR区域的比较。研究人员提出了一种IRs形成和演化的模型。DNA序列数据与复制过早终止或复制末端附近的不可逆染色体损伤后染色体拯救的新模型一致，涉及类似于人类癌细胞中形成非常大的ir的机制。我们假设L. delbrueckii ssp。保加利亚病菌在不同菌株中的特异性IR来源于至少93 kbp的单一祖先IR。
The first Lactobacillus delbrueckii ssp. bulgaricus genome sequence revealed the presence of a very large inverted repeat (IR), a DNA sequence arrangement which thus far seemed inconceivable in a non-manipulated circular bacterial chromosome, at the replication terminus. This intriguing observation prompted us to investigate if similar IRs could be found in other bacteria. IRs with sizes varying from 38 to 76 kbp were found at the replication terminus of all 5 L. delbrueckii ssp. bulgaricus chromosomes analysed, but in none of 1373 other chromosomes. They represent the first naturally occurring very large IRs detected in circular bacterial genomes. A comparison of the L. bulgaricus replication terminus regions and the corresponding regions without IR in 5 L. delbrueckii ssp. lactis genomes leads us to propose a model for the formation and evolution of the IRs. The DNA sequence data are consistent with a novel model of chromosome rescue after premature replication termination or irreversible chromosome damage near the replication terminus, involving mechanisms analogous to those proposed in the formation of very large IRs in human cancer cells. We postulate that the L. delbrueckii ssp. bulgaricus-specific IRs in different strains derive from a single ancestral IR of at least 93 kbp.
Mosaic：一个在线数据库，该数据库专用于细菌菌株的比较基因组学水平。
影响因子：
3
作者：
Chiapello H;Gendrault A;Caron C;Blum J;Petit MA;El Karoui M
通讯作者：
El Karoui M