title: Conservation and Role of Electrostatics in Thymidylate Synthase.
abstract: Conservation of function across families of orthologous enzymes is generally accompanied by conservation of their active site electrostatic potentials. To study the electrostatic conservation in the highly conserved essential enzyme, thymidylate synthase (TS), we conducted a systematic species-based comparison of the electrostatic potential in the vicinity of its active site. Whereas the electrostatics of the active site of TS are generally well conserved, the TSs from minimal organisms do not conform to the overall trend. Since the genomes of minimal organisms have a high thymidine content compared to other organisms, the observation of non-conserved electrostatics was surprising. Analysis of the symbiotic relationship between minimal organisms and their hosts, and the genetic completeness of the thymidine synthesis pathway suggested that TS from the minimal organism Wigglesworthia glossinidia (W.g.b.) must be active. Four residues in the vicinity of the active site of Escherichia coli TS were mutated individually and simultaneously to mimic the electrostatics of W.g.b TS. The measured activities of the E. coli TS mutants imply that conservation of electrostatics in the region of the active site is important for the activity of TS, and suggest that the W.g.b. TS has the minimal activity necessary to support replication of its reduced genome.
authors.affiliation: Molecular and Cellular Modeling Group, Heidelberg Institute for Theoretical Studies (HITS), Schloss-Wolfsbrunnenweg 35, 69118 Heidelberg, Germany.|Institute of Structural Biology, Helmholtz Zentrum München, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany.|Munich Center for Integrated Protein Science, Biomolecular NMR Spectroscopy, Department Chemie, Technische Universität München, Lichtenbergstrasse 4, 85747 Garching, Germany.
authors.forename: Divita
authors.initials: D
authors.lastname: Garg
authors.affiliation: Laboratoire d'Optique et Biosciences, Ecole Polytechnique, CNRS UMR7645, INSERM U1182, Université Paris-Saclay, 91128, Palaiseau, France.|Université Paris-Sud, 91405, Orsay, France.
authors.forename: Stephane
authors.initials: S
authors.lastname: Skouloubris
authors.affiliation: Laboratoire d'Optique et Biosciences, Ecole Polytechnique, CNRS UMR7645, INSERM U1182, Université Paris-Saclay, 91128, Palaiseau, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Briffotaux
authors.affiliation: Laboratoire d'Optique et Biosciences, Ecole Polytechnique, CNRS UMR7645, INSERM U1182, Université Paris-Saclay, 91128, Palaiseau, France.
authors.forename: Hannu
authors.initials: H
authors.lastname: Myllykallio
authors.affiliation: Molecular and Cellular Modeling Group, Heidelberg Institute for Theoretical Studies (HITS), Schloss-Wolfsbrunnenweg 35, 69118 Heidelberg, Germany.|Center for Molecular Biology (ZMBH), DKFZ-ZMBH Alliance, Heidelberg University, 69120 Heidelberg, Germany.|Interdisciplinary Center for Scientific Computing (IWR), Heidelberg University, Heidelberg, Baden-Württemberg, Germany.
authors.forename: Rebecca C
authors.initials: RC
authors.lastname: Wade
mesh_terms: D001665:Binding Sites; D020635:Buchnera / Q000737:chemistry / Q000201:enzymology*; D020134:Catalytic Domain; D003001:Cloning, Molecular; D003856:Deoxyuracil Nucleotides / Q000737:chemistry* / Q000378:metabolism; D057075:Enzyme Assays; D004926:Escherichia coli / Q000737:chemistry / Q000201:enzymology*; D005492:Folic Acid / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D015870:Gene Expression; D006801:Humans; D007700:Kinetics; D008958:Models, Molecular; D009154:Mutation; D055503:Protein Multimerization; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D055672:Static Electricity; D040681:Structural Homology, Protein; D013379:Substrate Specificity; D013940:Thymidylate Synthase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D044106:Wigglesworthia / Q000737:chemistry / Q000201:enzymology*
chemical_list: D003856:Deoxyuracil Nucleotides; D011994:Recombinant Proteins; C032418:5,11-methenyltetrahydrohomofolate; D005492:Folic Acid; C007267:2'-deoxyuridylic acid; D013940:Thymidylate Synthase