Whole-genome organization and functional properties of miniature DNA insertion sequences conserved in pathogenic Neisseriae
Whole-genome organization and functional properties of miniature DNA insertion sequences conserved in pathogenic Neisseriae
复制标题
DOI：
10.1016/s0378-1119(01)00725-9
复制
发表时间：
2001-10-31
期刊：
影响因子：
3.5
通讯作者：
Di Nocera, PP
中科院分区：
文献类型：
--
作者：
Mazzone, M;De Gregorio, E;Di Nocera, PP
致病奈瑟菌的染色体上布满了一个被称为Correia元素的小DNA序列的丰富家族的成员。这些DNA重复序列，我们称之为nemis（奈瑟菌微型插入序列），可以分为两大类。单位长度（154-158 bp）和内部重排（104-108 bp）的元件都具有长末端倒置重复序列（TIRs），并且可能折叠成坚固的茎环结构。Nemis是（或已经是）可移动的DNA序列，在插入时产生特定的2-by目标位点复制，并且严格召回RUP，这是在肺炎链球菌中发现的重复DNA元件。通过对脑膜炎奈瑟菌和淋病奈瑟菌基因组的全基因组计算机调查发现，26L/26R、26L/27R、27L/27R和27L/26R元件亚家族源于长度（26- 27bp）和序列内容（L型和R型）不同的TIRs组合。在这两个物种中，主要的亚家族是由26L/26R元素组成的。在脑膜炎奈瑟菌Z2491 （A血清组）和MC58 （B血清组）菌株中nemis的数量相当，但在淋病奈瑟菌F1090菌株中nemis的数量急剧减少。因此，在两种病原体中保守的几个基因仅在脑膜炎球菌基因组中被nemis DNA所包围。超过三分之二的nemis散布着单拷贝DNA，并且发现在离细胞基因很近的地方。引物延伸和RNase保护数据都支持了nemis与细胞基因共转录并随后在一个或两个tir上被特定的核糖核酸内切酶处理的观点，该酶似乎与RNase III相对应。(C) 2001 Elsevier Science B.V.版权所有
The chromosome of pathogenic Neisseriae is peppered by members of an abundant family of small DNA sequences known as Correia elements. These DNA repeats, that we call nemis (for neisseria miniature insertion sequences) can be sorted into two major size classes. Both unit-length (154-158 bp) and internally rearranged (104-108 bp) elements feature long terminal inverted repeats (TIRs), and can potentially fold into robust stem-loop structures. Nemis are (or have been) mobile DNA sequences which generate a specific 2-by target site duplication upon insertion, and strictly recall RUP, a repeated DNA element found in Streptococcus pneumoniae. The subfamilies of 26L/26R, 26L/27R, 27L/27R and 27L/26R elements, found by wide-genome computer surveys in both the Neisseria meningitidis and the Neisseria gonorrhoeae genomes, originate from the combination of TIRs which vary in length (26-27 bp) as in sequence content (L and R types). In both species, the predominant subfamily is made by the 26L/26R elements. The number of nemis is comparable in the N. meningitidis Z2491 (A serogroup) and the MC58 (B serogroup) strains, but is sharply reduced in the N. gonorrhoeae strain F1090. Consequently, several genes which are conserved in the two pathogens are flanked by nemis DNA in the meningococcus genome only. More than 2/3 of nemis are interspersed with single-copy DNA, and are found at close distance from cellular genes. Both primer extension and RNase protection data lend support to the notion that nemis are cotranscribed with cellular genes and subsequently processed, at either one or both TIRs, by a specific endoribonuclease, which plausibly corresponds to RNase III. (C) 2001 Elsevier Science B.V. All rights reserved.