Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Critical Care giúp cho các bạn có thêm kiến thức về ngành y học đề tài:Impacts of yeast metabolic network structure on enzyme evolution. | Correspondence Impacts of yeast metabolic network structure on enzyme evolution Chenqi Lu Ze Zhang Lindsey Leach MJ Kearsey and ZW Luo A comment on D Vitkup P Kharchenko and A Wagner Influence of metabolic network structure and function on enzyme evolution. Genome Biol 2006 7 R39. Addresses Laboratory of Population and Quantitative Genetics School of Life Sciences Institute of Biostatistics Fudan University Shanghai 200433 China. The Key Sericultural Laboratory of the Agricultural Ministry Southwest University Chongqing 400716 China. School of Biosciences University of Birmingham Edgbaston Birmingham B15 2TT UK. Correspondence ZW Luo. Email Published 9 August 2007 Genome Biology 2007 8 407 doi gb-2007-8-8-407 The electronic version of this article is the complete one and can be found online at http 2007 8 8 407 2007 BioMed Central Ltd Recently Vitkup et al. 1 investigated the influence of the yeast metabolic network structure and function on enzyme evolution. They calculated connectivity for each enzyme as the number of other metabolic enzymes that produce or consume its products or reactants and used it as its centrality measure in the network. They found that highly connected enzymes evolve more slowly than less connected enzymes are less likely to be essential compared to less connected enzymes and are more likely to retain duplicates in evolution. Metabolic networks exhibit a hierarchical modular structure in which some enzymes perform very specific local functions relevant only within a particular pathway whereas others may possess a global high-level role perhaps acting as mediators of distinct pathways 2 . In the graph theory the betweenness centrality measure of a node is defined as the number of shortest paths going through that node and is more appropriate for measuring the relative importance of a node in a network with hierarchical structure such as a metabolic network 3 . We first investigated whether .
