NMR solution structure of the acylphosphatase from Escherichia coli

The solution structure of Escherichia coli acylphosphatase (E. coli AcP), a small enzyme catalyzing the hydrolysis of acylphosphates, was determined by ¹H and ¹⁵N NMR and restrained modelling calculation. In analogy with the other members of AcP family, E. coli AcP shows an α/β sandwich domain composed of four antiparallel and one parallel β-strand, assembled in a five-stranded β-sheet facing two antiparallel α-helices. The pairwise RMSD values calculated for the backbone atoms of E. coli and Sulfolobus solfataricus AcP, Bovine common type AcP and Horse muscle AcP are 2.18, 5.31 and 5.12 Å, respectively. No significant differences are present in the active site region and the catalytic residue side chains are consistently positioned in the structures.