5caa

Publication Abstract from PubMed

Nucleoside diphosphate kinase (NDK) is a housekeeping enzyme that plays key roles in nucleotide recycling and homeostasis in trypanosomatids. Moreover, it is secreted by the intracellular parasite Leishmania to modulate the host response. These functions make NDK an attractive target for drug design and for studies aiming at a better understanding of the mechanisms mediating host-pathogen interactions. Here, we report the crystal structures of three mutants of the NDK from Leishmania major (LmNDK) that affects the stability of the hexameric biological assembly including P95S, Delta5Ct (lacking the last five residues) and the double mutant P100S/Delta5Ct. Although P95S and Delta5Ct variants conserve the hexameric structure of the wild-type protein, the double mutant becomes a dimer as shown by in solution studies. Free energy calculation of dimer-dimer interfaces and enzymatic assays indicate that P95S, Delta5Ct and P100S/Delta5Ct mutations progressively decrease the hexamer stability and enzyme activity. These results demonstrate that the mutated regions play a role in protein function through stabilizing the quaternary arrangement.

The role of the C-terminus and Kpn loop in the quaternary structure stability of nucleoside diphosphate kinase from Leishmania parasites.,Vieira PS, de Giuseppe PO, de Oliveira AH, Murakami MT J Struct Biol. 2015 Sep 26. pii: S1047-8477(15)30064-2. doi:, 10.1016/j.jsb.2015.09.009. PMID:26410384^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.