title: Phylogenetic and disruption analyses of aspartate kinase of Deinococcus radiodurans.
abstract: The extremely radioresistant bacterium Deinococcus radiodurans is evolutionarily closely related to the extremely thermophilic bacterium Thermus thermophilus. These bacteria have a single gene encoding an aspartate kinase (AK) that catalyzes the phosphorylation of L-aspartate. T. thermophilus has an aminoadipate pathway for lysine biosynthesis that does not use AK for lysine biosynthesis. Phylogenetic analysis in this study indicated that D. radiodurans AK has a different protein structure and a different evolutionary history from T. thermophilus AK. Disruption analysis of D. radiodurans AK indicated that D. radiodurans AK was not used for lysine biosynthesis but for threonine and methionine biosyntheses. A D. radiodurans AK disruption mutant exhibited a phenotype similar to a T. thermophilus AK disruption mutant, which indicates that these two AKs have different evolutionary origins, though their functions are not different.
authors.affiliation: Agricultural Bioinformatics Research Unit, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Tokyo, Japan. hnishida@iu.a.u-tokyo.ac.jp
authors.forename: Hiromi
authors.initials: H
authors.lastname: Nishida
authors.forename: Issay
authors.initials: I
authors.lastname: Narumi
mesh_terms: D001222:Aspartate Kinase / Q000235:genetics / Q000378:metabolism*; D005075:Biological Evolution; D003470:Culture Media; D034301:Deinococcus / Q000201:enzymology* / Q000235:genetics; D016680:Genome, Bacterial; D006715:Homoserine Dehydrogenase / Q000378:metabolism; D010802:Phylogeny; D011387:Prokaryotic Cells / Q000378:metabolism; D016963:Thermus thermophilus / Q000201:enzymology / Q000235:genetics
chemical_list: D003470:Culture Media; D006715:Homoserine Dehydrogenase; D001222:Aspartate Kinase