Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học quốc tế cung cấp cho các bạn kiến thức về ngành y đề tài: Chromatin architecture and gene expression in Escherichia coli. | Minireview Chromatin architecture and gene expression in Escherichia coli Hanni Willenbrock and David W Ussery Address Center for Biological Sequence Analysis Department of Biotechnology Building 208 Technical University of Denmark DK-2800 Kgs. Lyngby Denmark. Correspondence David W Ussery. E-mail dave@ Published I December 2004 Genome Biology 2004 5 252 The electronic version of this article is the complete one and can be found online at http 2004 5 12 252 2004 BioMed Central Ltd Abstract Two recent genome-scale analyses underscore the importance of DNA topology and chromatin structure in regulating transcription in Escherichia coli. Location location location Expression of a gene is in a sense a bit like purchasing a new home - the value is strongly dependent on location. This value is context-dependent it depends on who your neighbors are and also on the larger geographical picture. Two recent studies have analyzed DNA topology and chromatin structure on a genome-wide scale in Escherichia coli 1 2 . Both show that an important factor in determining transcription profiles - when and to what extent a gene is expressed - is the location of the gene within the context of the E. coli K-12 chromosome. Whereas this is old news for those who are interested mainly in eukaryotic chromosomes it is an important concept that has often been overlooked in our opinion in bacterial transcriptomics. In eukaryotes it is well known that there are two types of chromatin heterochromatin which remains condensed for the most part throughout the cell cycle and contains few genes and euchromatin which on the other hand contains gene-rich regions and in some cases clusters of highly expressed genes. Jeong et al. 1 analyzed similarities in the transcriptional activities of E. coli genes as a function of their position on the chromosome. An autocorrelation function identified three levels of spatial correlations of expressed genes shortrange 7-16 kilobase-pairs .
