Mechanism of antigenic variation in Mycoplasma pulmonis: Interwoven, site-specific DNA inversions
Mechanism of antigenic variation in Mycoplasma pulmonis: Interwoven, site-specific DNA inversions
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DOI：
10.1111/j.1365-2958.1995.mmi_18040703.x
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发表时间：
1995-11-01
影响因子：
3.6
通讯作者：
Dybvig, K
中科院分区：
文献类型：
--
作者：
Bhugra, B;Voelker, LL;Dybvig, K
鼠病原体肺支原体的染色体以高频率进行重排。我们发现，这些重排调节的相位可变的一组基因（vsa基因座）的表达，编码可变的V-1表面抗原。只有一个vsa基因与一个表达位点相关，其他的vsa基因是转录沉默的。沉默基因缺乏表达基因中存在的5'端区域（启动子和核糖体结合位点），并且DNA重排通过用来自先前沉默基因的3'端区域重新断言来自表达基因的5'端区域来调节基因表达。到目前为止鉴定的所有vsa重排都是位点特异性DNA倒位，其发生在每个vsa基因中保守的特定34 bp序列的拷贝之间。有趣的是，vsa基因座内的DNA倒位显然与hsd 1元件的倒位一致，hsd 1元件调节M中的限制和修饰活性。肺动脉
The chromosome of the murine pathogen Mycoplasma pulmonis undergoes rearrangements at a high frequency. We show that some of these rearrangements regulate the phase-variable expression of a cluster of genes (the vsa locus) that encode the variable V-l surface antigens. Only one vsa gene is associated with an expression site; the other vsa genes are transcriptionally silent. The silent genes lack the 5' end region (promoter and ribosome-binding site) that is present in the expressed gene, and DNA rearrangements regulate gene expression by reasserting the 5' end region from an expressed gene with the 3' end region from a previously silent gene. All vsa rearrangements identified so far are site-specific DNA inversions that occur between copies of a specific 34 bp sequence that is conserved in each vsa gene. Interestingly, DNA inversions within the vsa locus apparently occur in concert with inversion of the hsd1 element, which regulates restriction and modification activity in M. pulmonis.