Transplanting Allosteric Control of Enzyme Activity by Protein-Protein Interactions: Coupling a Regulatory Site to the Conserved Catalytic Core
Glycerol kinase from Escherichia coli, but not Haemophilus influenzae, is inhibited allosterically by phosphotransferase system protein IIAGlc. The primary structures of these related kinases contain 501 amino acids, differing at 117. IIAGlcinhibition is transplanted from E. coli glycerol kinase int...
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| Published in: | Proceedings of the National Academy of Sciences - PNAS Vol. 99; no. 17; pp. 11115 - 11120 |
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| Main Authors: | , |
| Format: | Journal Article |
| Language: | English |
| Published: |
United States
National Academy of Sciences
20-08-2002
National Acad Sciences |
| Subjects: | |
| Online Access: | Get full text |
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| Summary: | Glycerol kinase from Escherichia coli, but not Haemophilus influenzae, is inhibited allosterically by phosphotransferase system protein IIAGlc. The primary structures of these related kinases contain 501 amino acids, differing at 117. IIAGlcinhibition is transplanted from E. coli glycerol kinase into H. influenzae glycerol kinase by interconverting only 11 of the differences: 8 residues that interact with IIAGlcat the allosteric binding site and 3 residues in the conserved ATPase catalytic core that do not interact with IIAGlcbut the solvent accessible surface of which decreases when it binds. The three core residues are crucial for coupling the allosteric site to the conserved catalytic core of the enzyme. The site of the coupling residues identifies a regulatory locus in the sugar kinase/heat shock protein 70/actin superfamily and suggests relations between allosteric regulation and the active site closure that characterizes the family. The location of the coupling residues provides empirical validation of a computational model that predicts a coupling pathway between the IIAGlc-binding site and the active site [Luque, I. & Freire, E. (2000) Proteins Struct. Funct. Genet. Suppl. 4, 63-71]. The requirement for changes in core residues to couple the allosteric and active sites and switching from inhibition to activation by a single amino acid change are consistent with a postulated mechanism for molecular evolution of allosteric regulation. |
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| Bibliography: | Present address: Center for Neurodegenerative Disease Research, University of Pennsylvania, Medical Center & Health System, 3rd Floor Maloney Building, Hospital of the University of Pennsylvania, 3600 Spruce Street, Philadelphia, PA 19104-4283. To whom reprint requests should be addressed at: Department of Biochemistry and Biophysics, Texas A&M University, 2128 TAMU, College Station, TX 77843-2128. E-mail: dpettigrew@tamu.edu. Communicated by Saul Roseman, The Johns Hopkins University, Baltimore, MD Chimeric enzyme nomenclature: The chimeric enzymes are named according to the portions of primary structure from each of the parent enzymes; for example, H:E245 is joined at amino acid 245 with the N-terminal portion from HiGK and the C-terminal portion from EcGK, and HII:E423–442 is constructed by replacing amino acids 423–442 in HiGKII with those from EcGK. The II denotes the amino acid residues identified crystallographically to interact with IIAGlc (7). Single-letter amino acid abbreviations following a hyphen after the name of the chimera, e.g., HiGK–GTR, show the identities of the residues at positions 427–429. Individual amino acid substitutions are denoted by using the single-letter abbreviations, e.g. G427D indicates replacement of the glycine at 427 by aspartate. |
| ISSN: | 0027-8424 1091-6490 |
| DOI: | 10.1073/pnas.132393599 |