Nature Genetics 37, 1372 - 1375 (2005)
Published online: 20 November 2005; | doi:10.1038/ng1686
Adaptive evolution of bacterial metabolic networks by horizontal gene transferCsaba Pál1, 2, Balázs Papp2, 3
& Martin J Lercher1, 41
European Molecular Biology Laboratory, Meyerhofstrasse 1, D-69012 Heidelberg, Germany. 2
MTA, Theoretical Biology and Ecology Research Group, Eötvös Loránd University, Budapest H-1117, Hungary. 3
Faculty of Life Sciences, The University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK. 4
Department of Biology & Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK.
Correspondence should be addressed to Martin J Lercher lercher@embl.de Numerous studies have considered the emergence of metabolic pathways1, but the modes of recent evolution of metabolic networks are poorly understood. Here, we integrate comparative genomics with flux balance analysis to examine (i) the contribution of different genetic mechanisms to network growth in bacteria, (ii) the selective forces driving network evolution and (iii) the integration of new nodes into the network. Most changes to the metabolic network of Escherichia coli in the past 100 million years are due to horizontal gene transfer, with little contribution from gene duplicates. Networks grow by acquiring genes involved in the transport and catalysis of external nutrients, driven by adaptations to changing environments. Accordingly, horizontally transferred genes are integrated at the periphery of the network, whereas central parts remain evolutionarily stable. Genes encoding physiologically coupled reactions are often transferred together, frequently in operons. Thus, bacterial metabolic networks evolve by direct uptake of peripheral reactions in response to changed environments.
MORE ARTICLES LIKE THIS These links to content published by NPG are automatically generated.
|
