The Crystal Structure of Escherichia coli Spermidine Synthase SpeE Reveals a Unique Substrate-binding Pocket
Polyamines are essential in all branches of life. Biosynthesis of spermidine, one of the most ubiquitous polyamines, is catalyzed by spermidine synthase (SpeE). Although the function of this enzyme from Escherichia coli has been thoroughly characterized, its structural details remain unknown. Here, we report the crystal structure of E. coli SpeE and study its interaction with the ligands by isothermal titration calorimetry and computational modelling. SpeE consists of two domains - a small N-terminal {beta}-strand domain, and a C-terminal catalytic domain that adopts a canonical methyltransferase (MTase) Rossmann fold. The protein forms a dimer in the crystal and in solution. Structural comparison of E. coli SpeE to its homologs reveals that it has a large and unique substrate-binding cleft that may account for its lower amine substrate specificity.
- Research Organization:
- Brookhaven National Lab. (BNL), Upton, NY (United States). National Synchrotron Light Source
- Sponsoring Organization:
- DOE - OFFICE OF SCIENCE
- DOE Contract Number:
- DE-AC02-98CH10886
- OSTI ID:
- 1019848
- Report Number(s):
- BNL-95800-2011-JA; JSBIEM; TRN: US201115%%484
- Journal Information:
- Journal of Structural Biology, Vol. 169, Issue 3; ISSN 1047-8477
- Country of Publication:
- United States
- Language:
- English
Similar Records
Novel protein–protein interaction between spermidine synthase and S-adenosylmethionine decarboxylase from Leishmania donovani
Oligosaccharide Binding in Escherichia coli Glycogen Synthase