Putative binding mode of Escherichia coli exopolyphosphatase and polyphosphates based on a hybrid in silico/biochemical approach

BOETSCH, C; AGUAYO-VILLEGAS, D; GONZALEZ-NILO, FD; LISA, AT; BEASSONI, PR

ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS

ELSEVIER SCIENCE INC

Lugar: Amsterdam; Año: 2016 vol. 606 p. 64 - 72

0003-9861

The exopolyphosphatase of Escherichia coli processively and completely hydrolyses long polyphosphate chains to ortho-phosphate. Genetic surveys, based on the analysis of single ppx− or ppk− mutants and on the double mutant, demonstrate a relationship between these genes and the survival capacity. The exopolyphosphatase belongs to the ASKHA protein superfamily, hence, its active site is well known; however, the knowledge of the way in which this enzyme binds polyP remains incomplete. Here we present different computational approaches, site-direct mutagenesis and kinetic data to understand the relationship between structure and function of exopolyphosphatase. We propose H378 as a fundamental gatekeeper for the recognition of long chain polyphosphate.