Exploring structural features and potential lipid interactions of Pseudomonas aeruginosa type three secretion effector PemB by spectroscopic and calorimetric experiments.

Type Three Secretion System (T3SS) is a sophisticated nano-scale weapon utilized by several gram negative bacteria under stringent spatio-temporal regulation to manipulate and evade host immune systems in order to cause infection. To the best of our knowledge, this present study is the first report where we embark upon characterizing inherent features of native type three secretion effector protein PemB through biophysical techniques. Herein, first, we demonstrate binding affinity of PemB for phosphoinositides through isothermal calorimetric titrations.

Crystallographic and biophysical analyses of Pseudomonas aeruginosa ketopantoate reductase: Implications of ligand induced conformational changes in cofactor recognition.

Ketopantoate reductases (KPRs) catalyse NADPH-dependent reduction of ketopantoate to pantoate, the rate-limiting step of pantothenate biosynthetic pathway. In our recent study, we showed KPRs are under dynamic evolutionary selection and highlighted the possible role of ordered substrate binding kinetics for cofactor selection. To further delineate this at molecular level, here, we perform X-ray crystallographic and biophysical analyses of KPR in presence of non-canonical cofactor NAD.