Promoter islands as a platform for interaction with nucleoid proteins and transcription factors.
Seventy-eight promoter islands with an extraordinarily high density of potential promoters have been recently found in the genome of Escherichia coli. It has been shown that RNA polymerase binds internal promoters of these islands and produces short oligonucleotides, while the synthesis of normal mRNAs is suppressed. This quenching may be biologically relevant, as most islands are associated with foreign genes, which expression may deplete cellular resources. However, a molecular mechanism of silencing with the participation of these promoter-rich regions remains obscure. It has been demonstrated that all islands interact with histone-like protein H-NS--a specific sentinel of foreign genes. In this study, we demonstrated the inhibitory effect of H-NS using Δhns mutant of Escherichia coli and showed that deletion of dps, encoding another protein of bacterial nucleoid, tended to decrease rather than increase the amount of island-specific transcripts. This observation precluded consideration of promoter islands as sites for targeted heterochromatization only and a computer search for the binding sites of 53 transcription factors (TFs) revealed six proteins, which may specifically regulate their transcriptional output.
Department of Functional Genomics and Cellular Stress, Institute of Cell Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region 142290, Russia.
Yuri A
YA
Purtov
Olga A
OA
Glazunova
Sergey S
SS
Antipov
Viktoria O
VO
Pokusaeva
Eugeny E
EE
Fesenko
Elena V
EV
Preobrazhenskaya
Konstantin S
KS
Shavkunov
Maria N
MN
Tutukina
Viktor I
VI
Lukyanov
Olga N
ON
Ozoline
D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D001665:Binding Sites; D004268:DNA-Binding Proteins / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics; D044404:Genomic Islands / Q000235:genetics*; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011485:Protein Binding; D014157:Transcription Factors / Q000235:genetics*; D015533:Transcriptional Activation / Q000235:genetics
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C083911:DPS protein, Bacteria; D014157:Transcription Factors