Structural highlights
Function
SPEE_ECOLI Involved in the biosynthesis of polyamines which play a significant role in the structural and functional organization in the chromoid of E.coli by compacting DNA and neutralizing negative charges. Catalyzes the irreversible transfer of a propylamine group from the amino donor S-adenosylmethioninamine (decarboxy-AdoMet) to putrescine (1,4-diaminobutane) to yield spermidine. Cadaverine (1,5-diaminopentane) and spermidine can replace putrescine as the propylamine acceptor.[1] [2]
Evolutionary Conservation
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Publication Abstract from PubMed
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 characterised, 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.
The crystal structure of Escherichia coli spermidine synthase SpeE reveals a unique substrate-binding pocket.,Zhou X, Chua TK, Tkaczuk KL, Bujnicki JM, Sivaraman J J Struct Biol. 2010 Mar;169(3):277-85. Epub 2010 Jan 4. PMID:20051267[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Lee MJ, Yang YT, Lin V, Huang H. Site-directed mutations of the gatekeeping loop region affect the activity of Escherichia coli spermidine synthase. Mol Biotechnol. 2013 Jun;54(2):572-80. doi: 10.1007/s12033-012-9599-3. PMID:23001854 doi:http://dx.doi.org/10.1007/s12033-012-9599-3
- ↑ Bowman WH, Tabor CW, Tabor H. Spermidine biosynthesis. Purification and properties of propylamine transferase from Escherichia coli. J Biol Chem. 1973 Apr 10;248(7):2480-6. PMID:4572733
- ↑ Zhou X, Chua TK, Tkaczuk KL, Bujnicki JM, Sivaraman J. The crystal structure of Escherichia coli spermidine synthase SpeE reveals a unique substrate-binding pocket. J Struct Biol. 2010 Mar;169(3):277-85. Epub 2010 Jan 4. PMID:20051267 doi:10.1016/j.jsb.2009.12.024
