Archaeal ADP-dependent phosphofructokinase: expression, purification, crystallization and preliminary crystallographic analysis

Thermococcus litoralis uses a modified Embden–Meyerhof pathway. Its phosphofructokinase (TLPFK) catalyses the phosphorylation of fructose‐6‐phosphate by ADP, but not by ATP, in the presence of Mg2+, yielding fructose‐1,6‐bisphosphate. The gene encoding TLPFK was cloned and overexpressed in Escherichia coli. Recombinant TLPFK consists of a dimer with a 52 kDa subunit. The native crystals belong to space group P41212, with unit‐cell parameters a = b = 85.41, c = 163.93 Å, and diffract to beyond 2.6 Å resolution. The TLPFK structure was preliminarily analyzed by means of multiple isomorphous replacement with four heavy‐atom derivatives.