The histidine-phosphocarrier protein of the phosphoenolpyruvate: sugar phosphotransferase system of Bacillus sphaericus self-associates.
The phosphotransferase system (PTS) is involved in the use of carbon sources in bacteria. Bacillus sphaericus, a bacterium with the ability to produce insecticidal proteins, is unable to use hexoses and pentoses as the sole carbon source, but it has ptsHI genes encoding the two general proteins of the PTS: enzyme I (EI) and the histidine phosphocarrier (HPr). In this work, we describe the biophysical and structural properties of HPr from B. sphaericus, HPr(bs), and its affinity towards EI of other species to find out whether there is inter-species binding. Conversely to what happens to other members of the HPr family, HPr(bs) forms several self-associated species. The conformational stability of the protein is low, and it unfolds irreversibly during heating. The protein binds to the N-terminal domain of EI from Streptomyces coelicolor, EIN(sc), with a higher affinity than that of the natural partner of EIN(sc), HPr(sc). Modelling of the complex between EIN(sc) and HPr(bs) suggests that binding occurs similarly to that observed in other HPr species. We discuss the functional implications of the oligomeric states of HPr(bs) for the glycolytic activity of B. sphaericus, as well as a strategy to inhibit binding between HPr(sc) and EIN(sc).
Instituto de Biología Molecular y Celular, Universidad Miguel Hernández, Elche, Alicante, Spain.
Rosa
R
Doménech
José G
JG
Hernández-Cifre
Julio
J
Bacarizo
Ana I
AI
Díez-Peña
Sergio
S
Martínez-Rodríguez
Claudio N
CN
Cavasotto
José García
JG
de la Torre
Ana
A
Cámara-Artigás
Adrián
A
Velázquez-Campoy
José L
JL
Neira
D001407:Bacillus / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D002151:Calorimetry; D006639:Histidine; D006358:Hot Temperature; D057446:Hydrodynamics; D006863:Hydrogen-Ion Concentration; D008958:Models, Molecular; D010455:Peptides; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System / Q000737:chemistry / Q000378:metabolism*; D010766:Phosphorylation; D011485:Protein Binding; D011489:Protein Denaturation; D017510:Protein Folding; D017433:Protein Structure, Secondary; D013050:Spectrometry, Fluorescence; D048372:Streptomyces coelicolor / Q000378:metabolism; D013816:Thermodynamics
D001426:Bacterial Proteins; D010455:Peptides; D006639:Histidine; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System; C030182:phosphocarrier protein HPr