Structural and binding studies of phosphopantetheine adenylyl transferase from Acinetobacter baumannii

Publication date: Available online 15 March 2019Source: Biochimica et Biophysica Acta (BBA) - Proteins and ProteomicsAuthor(s): A. Gupta, P.K. Singh, N. Iqbal, P. Sharma, H.R. Baraigya, P. Kaur, M.S. Umar, F. Ahmad, A. Sharma, M. Owais, S. Sharma, T.P. SinghAbstractPhosphopantetheine adenylyltransferase (PPAT, EC. 2.7.7.3) catalyzes an essential step in the reaction that transfers an adenylyl group from adenosine tri phosphate (ATP) to 4′-phosphopantetheine (pPant) yielding 3′- dephospho-coenzyme A (dPCoA) and pyrophosphate (PP) in the coenzyme A (CoA) biosynthesis pathway. The enzyme PPAT from Acinetobacter baumannii (AbPPAT) was cloned, expressed and purified. The binding studies of AbPPAT were carried out with two compounds, tri‑sodium citrate (TSC) and l-ascorbic acid (LAA, vitamin-C) using fluorescence spectroscopic (FS) and surface Plasmon resonance (SPR) methods. Both methods provided similar values of dissociation constants for TSC and LAA which were of the order of 10−8 M and 10−5 M respectively. The computer aided docking studies indicated fewer interactions of LAA with AbPPAT as compared to those of TSC. The freshly purified samples of AbPPAT were crystallized. The crystals of AbPPAT were soaked in the solutions containing TSC and LAA. However, the crystals of the complex of AbPPAT with LAA did not diffract well and hence the structure of the complex of AbPPAT with LAA could not be determined. On the other hand, the crystals of the complex of AbPPAT w...
Source: Biochimica et Biophysica Acta (BBA) Proteins and Proteomics - Category: Biochemistry Source Type: research