Structural and computational studies of the Staphylococcus aureus sortase B-substrate complex reveal a substrate-stabilized oxyanion hole
| Autor: | Brendan R. Amer, Michael E. Jung, Robert T. Clubb, Sung Wook Yi, Grace L. Huang, Michael R. Sawaya, Alex W. Jacobitz, Angelyn V. Nguyen, Jeff Wereszczynski, J. Andrew McCammon |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2014 |
| Předmět: |
Staphylococcus aureus
Biochemistry & Molecular Biology Cell Surface Enzymes Stereochemistry 1.1 Normal biological development and functioning Enzyme Mechanisms Bioengineering Protein Sorting Signals Molecular Dynamics Simulation Crystallography X-Ray Arginine Molecular Dynamics Biochemistry Medical and Health Sciences Fimbriae Residue (chemistry) chemistry.chemical_compound Bacterial Proteins Sortase Catalytic Domain Enzyme Stability Molecular Biology Crystallography biology C-terminus Bacterial Active site Substrate (chemistry) Hydrogen Bonding Cell Biology Biological Sciences Aminoacyltransferases Oxygen Cysteine Endopeptidases Emerging Infectious Diseases Infectious Diseases chemistry Generic Health Relevance Fimbriae Bacterial Chemical Sciences biology.protein X-Ray Biocatalysis Crystal Structure Peptidoglycan Oxyanion hole Molecular Biophysics |
| Zdroj: | Jacobitz, AW; Wereszczynski, J; Yi, SW; Amer, BR; Huang, GL; Nguyen, AV; et al.(2014). Structural and computational studies of the Staphylococcus aureus sortase B-substrate complex reveal a substrate-stabilized oxyanion hole. Journal of Biological Chemistry, 289(13), 8891-8902. doi: 10.1074/jbc.M113.509273. UC San Diego: Retrieved from: http://www.escholarship.org/uc/item/2928d1bp The Journal of biological chemistry, vol 289, iss 13 |
| Popis: | Sortase cysteine transpeptidases covalently attach proteins to the bacterial cell wall or assemble fiber-like pili that promote bacterial adhesion. Members of this enzyme superfamily are widely distributed in Gram-positive bacteria that frequently utilize multiple sortases to elaborate their peptidoglycan. Sortases catalyze transpeptidation using a conserved active site His-Cys-Arg triad that joins a sorting signal located at the C terminus of their protein substrate to an amino nucleophile located on the cell surface. However, despite extensive study, the catalytic mechanism and molecular basis of substrate recognition remains poorly understood. Here we report the crystal structure of the Staphylococcus aureus sortase B enzyme in a covalent complex with an analog of its NPQTN sorting signal substrate, revealing the structural basis through which it displays the IsdC protein involved in heme-iron scavenging from human hemoglobin. The results of computational modeling, molecular dynamics simulations, and targeted amino acid mutagenesis indicate that the backbone amide of Glu224and the side chain of Arg233form an oxyanion hole in sortase B that stabilizes high energy tetrahedral catalytic intermediates. Surprisingly, a highly conserved threonine residue within the bound sorting signal substrate facilitates construction of the oxyanion hole by stabilizing the position of the active site arginine residue via hydrogen bonding. Molecular dynamics simulations and primary sequence conservation suggest that the sorting signal-stabilized oxyanion hole is a universal feature of enzymes within the sortase superfamily. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|