tailieunhanh - Báo cáo y học: "Structural and functional map of a bacterial nucleoid"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Wertheim cung cấp cho các bạn kiến thức về ngành y đề tài: Structural and functional map of a bacterial nucleoid. | X Genome Biology Minireview Structural and functional map of a bacterial nucleoid Agustino Martinez-Antonio Alejandra Medina-Riverat and Julio Collado-Videst Addresses Departamento de Ingenieria Genética Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional Irapuato 36500 México. tprograma de Genómica Computacional Centro de Ciencias Genómicas Universidad Nacional Autónoma de México Cuernavaca Morelos México. Correspondence Julio Collado-Vides. Email collado@ Agustino Martinez-Antonio. Email amartinez@ Abstract Genome-wide mapping of transcription factor-DNA interactions in bacterial chromosomes in vivo has begun to reveal global zones occupied by these factors that serve two purposes compacting the bacterial DNA and influencing global programs of gene transcription. In single-celled organisms such as bacteria economy is critical including the efficient use of space in the tiny cell. Although gene density in bacterial genomes is high the chromosomes are still long macromolecules that must be compacted by at least three orders of magnitude to fit into the space available 1 2 and the mechanism of chromosomal packing in bacteria and the proteins involved is a long-standing question. In a recent study published in Molecular Cell Saeed Tavoizie and colleagues Vora et al. 3 have investigated protein binding across the complete Escherichia coli genome and have revealed extended regions of high protein occupancy. Together with other recent studies this work provides valuable information on the chromosomal organization by DNA-binding proteins in bacteria and will aid understanding of their large-scale effects on gene expression. Chromosomal size and dynamics in bacteria A bacterial genome typically comprises a single circular DNA molecule usually between and 10 Mbp in free-living bacteria 4 5 which in vivo is packaged with proteins into a distinct structure known as the bacterial nucleoid. The information encoded .