title: The Fic protein Doc uses an inverted substrate to phosphorylate and inactivate EF-Tu.
abstract: Fic proteins are ubiquitous in all of the domains of life and have critical roles in multiple cellular processes through AMPylation of (transfer of AMP to) target proteins. Doc from the doc-phd toxin-antitoxin module is a member of the Fic family and inhibits bacterial translation by an unknown mechanism. Here we show that, in contrast to having AMPylating activity, Doc is a new type of kinase that inhibits bacterial translation by phosphorylating the conserved threonine (Thr382) of the translation elongation factor EF-Tu, rendering EF-Tu unable to bind aminoacylated tRNAs. We provide evidence that EF-Tu phosphorylation diverged from AMPylation by antiparallel binding of the NTP relative to the catalytic residues of the conserved Fic catalytic core of Doc. The results bring insights into the mechanism and role of phosphorylation of EF-Tu in bacterial physiology as well as represent an example of the catalytic plasticity of enzymes and a mechanism for the evolution of new enzymatic activities.
authors.affiliation: Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Baddiley-Clark Building, Richardson Road, Newcastle upon Tyne, NE2 4AX, UK.
authors.forename: Daniel
authors.initials: D
authors.lastname: Castro-Roa
authors.affiliation: Structural Biology Brussels, Department of Biotechnology (DBIT), Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium.|Molecular Recognition Unit, Department of Structural Biology, VIB, Pleinlaan 2, B-1050 Brussels, Belgium.
authors.forename: Abel
authors.initials: A
authors.lastname: Garcia-Pino
authors.affiliation: Structural Biology Brussels, Department of Biotechnology (DBIT), Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium.|Molecular Recognition Unit, Department of Structural Biology, VIB, Pleinlaan 2, B-1050 Brussels, Belgium.
authors.forename: Steven
authors.initials: S
authors.lastname: De Gieter
authors.affiliation: Structural Biology Brussels, Department of Biotechnology (DBIT), Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium.|Molecular Recognition Unit, Department of Structural Biology, VIB, Pleinlaan 2, B-1050 Brussels, Belgium.
authors.forename: Nico A J
authors.initials: NAJ
authors.lastname: van Nuland
authors.affiliation: Structural Biology Brussels, Department of Biotechnology (DBIT), Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium.|Molecular Recognition Unit, Department of Structural Biology, VIB, Pleinlaan 2, B-1050 Brussels, Belgium.
authors.forename: Remy
authors.initials: R
authors.lastname: Loris
authors.affiliation: Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Baddiley-Clark Building, Richardson Road, Newcastle upon Tyne, NE2 4AX, UK.
authors.forename: Nikolay
authors.initials: N
authors.lastname: Zenkin
mesh_terms: D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D006160:Guanosine Triphosphate / Q000235:genetics / Q000378:metabolism; D008958:Models, Molecular; D009154:Mutation; D009713:Nucleotidyltransferases / Q000235:genetics / Q000378:metabolism*; D010444:Peptide Elongation Factor Tu / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation; D017510:Protein Folding; D012343:RNA, Transfer / Q000235:genetics / Q000378:metabolism
chemical_list: D029968:Escherichia coli Proteins; D006160:Guanosine Triphosphate; D012343:RNA, Transfer; D009713:Nucleotidyltransferases; D010444:Peptide Elongation Factor Tu