Castang Sandra, McManus Heather R, Turner Keith H, Dove Simon L
Division of Infectious Diseases, Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.
Proc Natl Acad Sci U S A. 2008 Dec 2;105(48):18947-52. doi: 10.1073/pnas.0808215105. Epub 2008 Nov 21.
The histone-like nucleoid structuring protein, H-NS, is a prominent global regulator of gene expression. Many Gram-negative bacteria contain multiple members of the H-NS family of proteins. Thus, a key question is whether H-NS family members have overlapping or distinct functions. To address this question we performed genome-wide location analyses with MvaT and MvaU, the two H-NS family members present in Pseudomonas aeruginosa. We show that MvaT and MvaU bind the same chromosomal regions, coregulating the expression of approximately 350 target genes. We show further that like H-NS in enteric bacteria, which functions as a transcriptional silencer of foreign DNA by binding to AT-rich elements, MvaT and MvaU bind preferentially to AT-rich regions of the chromosome. Our findings establish that H-NS paralogs can function coordinately to regulate expression of the same set of target genes, and suggest that MvaT and MvaU are involved in silencing foreign DNA elements in P. aeruginosa.
类组蛋白核仁结构蛋白H-NS是一种重要的全局基因表达调控因子。许多革兰氏阴性菌含有多个H-NS蛋白家族成员。因此，一个关键问题是H-NS家族成员的功能是重叠还是不同。为了解决这个问题，我们对铜绿假单胞菌中存在的两个H-NS家族成员MvaT和MvaU进行了全基因组定位分析。我们发现MvaT和MvaU结合相同的染色体区域，共同调控约350个靶基因的表达。我们进一步表明，与肠道细菌中的H-NS一样，H-NS通过与富含AT的元件结合而作为外源DNA的转录沉默子，MvaT和MvaU优先结合染色体的富含AT的区域。我们的研究结果表明，H-NS旁系同源物可以协同作用来调控同一组靶基因的表达，并表明MvaT和MvaU参与了铜绿假单胞菌中外源DNA元件的沉默。
