Cloning, purification and characterization of the ribosomal protein L11 from E. coli

A high-expression system of L11 was constructed and investigated its interaction with other elements of the ribosome using physicochemical methods. The gene rplK, coding for the protein L11 from the E. coli 50S ribosomal subunit was amplifyied, cloned and over-expressed. The protein L11 was purified under native and denaturing conditions, refolded and the structure of both proteins was compared. The protein L11 properly refolded from 6M urea after dialysis. Experiments on binding of proteins L11, RRF and EF-G from Escherichia coli were performed by ana-lytical centrifugation and Biacore. Specific binding between protein L11 and RRF by analytical cen-trifugation was not detected probably due to struc-tural reasons. These findings may be helpful in the design of new antibiotics that specifically disrupt the interactions in the “GTP-associated site” of the bac-terial ribosome, as many of them are not effective anymore. A common intrinsically disordered region of protein L11 was found to be the amino acid se-quence 86-97, while the residues 67-74, containing the linker region, are predicted to be disordered by DisEMBL.

Diagnostic Strategies and Treatment for Ewing’s Sarcoma

Ewing’s sarcoma is an enigmatic malignancy of progenitor cell origin, driven by transcription factor oncogenic fusions. About 85% of ESFT cases harbor the t(11;22) translocation and express the fusion protein EWS-FLI. Both bone marrow-derived human Mesenchymal stem cells and Neural crest stem cells are permissive for EWS-FLI1 expression that initiates transition to ESFT-like cellular phenotype. Diagnosis of Ewing’s tumor is based on pathologic and molecular findings. The hypoxia enhances the malignancy of ESFT invasive capacity. An ALDHhigh subpopulation of Ewing’s sarcoma cells, capable of self-renewal, tumor initiation and resistant to chemotherapy in vitro, are not resistant to YK-4-279. Intensive high-dose chemotherapy followed by stem-cell reconstitution was used for ESFT patients in second remission. Plerixafor in combination with G-CSF is an effective enhance stem cell mobilization regimen for stem cell collection with lowest success rate in patients with neuroblastoma. The ESFT-derived antigens EZH2(666) and CHM1(319) are suitable targets for protective allo-restricted human CD8(+) T-cell responses against non-immunogenic ESFT. Primitive neuroectodermal features and MSC origin are both compatible with G(D2) aberrant expression and explore G(D2) immune targeting in ESFT.

Disorder structural predictions of the native EWS and its oncogenic fusion proteins in rapport with the function

The Intrinsic structural disorder (ISD) of native EWS and its fusion oncogenic proteins, including EWS/FliI, EWS/ATF1 and EWS/ZSG, was estimated by different Predictors. The ISD difference between the wild type and the oncogenic fusions found in the CTD is due to the fusion partner, usually a transcription factor (TF). A disordered region was found in the sequence (AA 132 - 156) of the NTD (EAD) of EWS, consisting of the longest region free of Y motifs. The IQ domain (AA 258 - 280), a Y-free region, flanked by two Y-boxes, is also disordered by all used Predictors. The EWS functional regions RGG1, RGG2 and RGG3 are predominantly disordered. A strong dependence was found between the structure of EWS protein and its oncogenic fusions, and their estimated ISD. The oncogenic function of the fusions is related to a decreased ISD in the CTD, due to the fused TF. The Predictors shown that the different isoforms have similar profiles, shifted with some amino acids, due to the translocations. On the bases of the prediction results, an analysis was made of the EWS sequence and its functional regions with increased ISD to make a relationship sequence-disorder-function that could be helpful in the design of antitumor agents against the corresponding malignances.