title: Structure and function of Escherichia coli RimK, an ATP-grasp fold, L-glutamyl ligase enzyme.
abstract: We report herein the crystal structure of Escherichia coli RimK at a resolution of 2.85 Å, an enzyme that catalyzes the post-translational addition of up to 15 C-terminal glutamate residues to ribosomal protein S6. The structure belongs to the ATP-grasp superfamily and is organized as a tetramer, consistent with gel filtration analysis. Each subunit consists of three distinct structural domains and the active site is located in the cleft between these domains. The catalytic reaction appears to occur at the junction between the three domains as ATP binds between the B and C domains, and other substrates bind nearby.
authors.affiliation: Department of Integrative Systems Biology, Center for Genetic Medicine Research, Children's National Medical Center, The George Washington University, Washington, DC, 20010.
authors.forename: Gengxiang
authors.initials: G
authors.lastname: Zhao
authors.forename: Zhongmin
authors.initials: Z
authors.lastname: Jin
authors.forename: Yanli
authors.initials: Y
authors.lastname: Wang
authors.forename: Norma M
authors.initials: NM
authors.lastname: Allewell
authors.forename: Mendel
authors.initials: M
authors.lastname: Tuchman
authors.forename: Dashuang
authors.initials: D
authors.lastname: Shi
mesh_terms: D000244:Adenosine Diphosphate / Q000737:chemistry / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000737:chemistry / Q000378:metabolism; D001665:Binding Sites; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000378:metabolism; D008958:Models, Molecular; D010453:Peptide Synthases / Q000737:chemistry / Q000378:metabolism; D011487:Protein Conformation; D017510:Protein Folding
chemical_list: D029968:Escherichia coli Proteins; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D010453:Peptide Synthases; C022414:polyglutamyl synthetase
keywords: ATP-grasp fold; RimK enzyme; folypolyglutamate synthetase; poly-α-glutamate synthetase; post-translational modification of ribosomal protein