H-NS OVER-EXPRESSION INDUCES AN ARTIFICIAL STATIONARY-PHASE BY SILENCING GLOBAL TRANSCRIPTION
H-NS OVER-EXPRESSION INDUCES AN ARTIFICIAL STATIONARY-PHASE BY SILENCING GLOBAL TRANSCRIPTION
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DOI：
10.1016/0300-9084(94)90026-4
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发表时间：
1994-01-01
期刊：
影响因子：
3.9
通讯作者：
JAWORSKI, A
中科院分区：
文献类型：
--
作者：
MCGOVERN, V;HIGGINS, NP;JAWORSKI, A
细菌通过拓扑异构酶和一组小(10-20 kDa)蛋白质的作用，将它们的染色体组织成一个复杂的相互缠绕的超螺旋结构，称为类核。两种最丰富的类核相关蛋白是HU和H-NS。在稳定期，H-NS的丰度增加。HU的过度表达具有很好的耐受性，并与转录和细胞生长相容。增加H-NS的浓度会导致全球转录的快速沉默，并产生一种让人想起静止阶段的生长停滞状态。在转录停止期间，H-NS的过度表达也会导致质粒DNA中超螺旋的大量丧失。通过比较这两种蛋白质过度表达的效果，可以更深入地了解这两种蛋白质在染色体活动中的不同作用。用类核组织模型解释了这些观测结果。
Bacteria organize their chromosomes in a complex interwound supercoiled structure called the nucleoid through the action of topoisomerases and a set of small (10-20 kDa) proteins. The two most abundant nucleoid-associated proteins are HU and H-NS. H-NS increases in abundance during stationary phase. Over-expression of HU is well tolerated and compatible with transcription and cell growth. Increasing the concentration of H-NS leads to a rapid silencing of global transcription and produces a growth-arrested state reminiscent of stationary phase. H-NS over-expression also induces a substantial loss of supercoiling in plasmid DNA during the time that transcription is arrested. Comparing the effects of over-expression of these two proteins gives some insight into the differential roles of these proteins in the activity of the chromosome. These observations are interpreted in a model of nucleoid organization.