PURIFICATION AND CHARACTERIZATION OF THE ESCHERICHIA-COLI THERMORESISTANT GLUCONOKINASE ENCODED BY THE GNTK GENE

A thermoresistant gluconokinase encoded by the gutK gene of Escherichi a coli K-12 was purified and characterized. The K-m values of the puri fied enzyme for gluconate and ATP are 42 mu M and 123 mu M, respective ly, and the activity was not altered by the presence of pyruvate, The enzyme was shown to function as a dimer with two identical subunits of 18.4 kDa. These characteristics appear to be distinct from those of t he gluconokinase reported by E.I. Vivas, A, Liendo, K. Dawidowicz, and T. Isturiz (1994) J. Basic, Microbiol. 16, 117-122.