Isolation and in silico characterization of a shikimate kinase from Cassia obtusifolia

Shikimate kinase (SK), an indispensable enzyme in shikimate pathway, catalyzes the transfer of a phosphate from Adenosine triphosphate (ATP) to 3-hydroxyl of shikimate to form shikimate 3-phosphate. There are many active metabolites from shikimate pathway in Cassia obtusifolia. A new member of SKs from C. obtusifolia named CoSK was cloned and subjected to in silico characterization analysis. The constructed 3D structure of CoSK adopted α-β-α fold with five parallel β-sheets flanked by 12 α-helices. CoSK was shown to possess the potential ability to catalyze the phosphorylation of shikimate. Residues Lys118 and Arg223 binding with ATP and residue Asp137 binding with shikimate might be essential for phosphorylating shikimate. These results will provide useful information concerning the catalytic and physiology mechanism of SK in plants.