MetaCyc Enzyme: shikimate kinase

Gene: SK1 Accession Number: AT2G21940 (MetaCyc)

Species: Arabidopsis thaliana col

SK1 is one of two shikimate kinases from Arabidopsis thaliana that phosphorylate shikimate. As part of the shikimate pathway, these enzymes help to move carbon from primary metabolism to a broad range of secondary metabolites important for plant growth, development, and survival under stress [Fucile08].

Although they have relatively similar enzymatic activities, SK1 and SK2 expression patterns are different with SK1 transcripts being expressed most highly in mature embryos and senescing leaves while SK2 transcripts are expressed throughout vegetative development and early on during embryogenesis. In addition, SK1 transcripts rise during heat stress and recovery, whereas SK2 has higher levels of transcripts following innoculation with spores of Phytophthora infestans [Fucile08].

It is believed that this protein is found in the chloroplast based on the presence of a putative N-terminal transit peptide and based on the observation that shikimate kinases from spinach and tomato are targeted to the chloroplast [Schmidt90, Schmid92, Fucile08].

Unification Links: ArrayExpress:Q9SJ05 , PhylomeDB:Q9SJ05 , Phytozome Plant Orthologs:AT2G21940.4 , Pride:Q9SJ05 , Protein Model Portal:Q9SJ05 , SMR:Q9SJ05 , String:Q9SJ05 , TAIR:AT2G21940 , UniProt:Q9SJ05

Relationship Links: InterPro:IN-FAMILY:IPR000623 , InterPro:IN-FAMILY:IPR023000 , InterPro:IN-FAMILY:IPR027417 , Pfam:IN-FAMILY:PF01202 , Prints:IN-FAMILY:PR01100 , Prosite:IN-FAMILY:PS01128

Gene-Reaction Schematic: ?

Gene-Reaction Schematic

Created 06-Dec-2010 by Dreher KA , TAIR

Enzymatic reaction of: shikimate kinase

EC Number:

shikimate + ATP <=> shikimate 3-phosphate + ADP + H+

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.

This reaction is reversible.

In Pathways: chorismate biosynthesis I

A recombinant form of this enzyme was characterized that lacked the first 55 amino acids, which are predicted to be part of a chloroplast N-terminal transit peptide. The approximate molecular mass of the truncated protein was 27.8 kDa [Fucile08].

The kcat for shikimate was 148.45 +/- 2.32 s-1 and for ATP was 162.43 +/- 3.01 s-1 [Fucile08].

Cofactors or Prosthetic Groups: Mg2+ [Fucile08]

Kinetic Parameters:

Km (μM)

pH(opt): 8.0 [Fucile08]


Fucile08: Fucile G, Falconer S, Christendat D (2008). "Evolutionary diversification of plant shikimate kinase gene duplicates." PLoS Genet 4(12);e1000292. PMID: 19057671

Schmid92: Schmid J, Schaller A, Leibinger U, Boll W, Amrhein N (1992). "The in-vitro synthesized tomato shikimate kinase precursor is enzymatically active and is imported and processed to the mature enzyme by chloroplasts." Plant J 2(3);375-83. PMID: 1338949

Schmidt90: Schmidt CL, Danneel HJ, Schultz G, Buchanan BB (1990). "Shikimate kinase from spinach chloroplasts : purification, characterization, and regulatory function in aromatic amino Acid biosynthesis." Plant Physiol 93(2);758-66. PMID: 16667533

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Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
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