Pathological significance of interaction of Synphilin-1 with mutated alpha-synuclein is well known to have serious consequences in causing the formation of inclusion bodies that are linked to Parkinson's disease (PD). Information extracted so far pointed out that specific mutations, A53T, A30P, and E46K, in alpha-synuclein promote such interactions. However, a detailed structural study of this interaction is pending due to the unavailability of the complete structures of the large protein Synphilin-1 of chain length 919 residues and the mutated alpha-synuclein having all the reported specific mutations so far.
View Article and Find Full Text PDFDiscovery of intrinsically disordered proteins (IDPs) and protein hybrids that contain both intrinsically disordered protein regions (IDPRs) along with ordered regions has changed the sequence-structure-function paradigm of protein. These proteins with lack of persistently fixed structure are often found in all organisms and play vital roles in various biological processes. Some of them are considered as potential drug targets due to their overrepresentation in pathophysiological processes.
View Article and Find Full Text PDFBioinformation
January 2023
is an opportunistic pathogen that causes variety of infections range from mild skin diseases to life-threatening sepsis. It is also notorious for acquiring resistance to numerous antibiotics. Parvulin-type peptidyl-prolyl cis-trans isomerase (PPiase) domain containing PrsA protein is considered as an essential folding factor for secreted proteins of Gram-positive bacteria.
View Article and Find Full Text PDFBackground: Concurrent existence of lncRNA and circular RNA at both nucleus and cytosol within a cell at different proportions is well reported. Previous studies showed that circular RNAs are synthesized in nucleus followed by transportation across the nuclear membrane and the export is primarily defined by their length. lncRNAs primarily originated through inefficient splicing and seem to use NXF1 for cytoplasm export.
View Article and Find Full Text PDFIEEE/ACM Trans Comput Biol Bioinform
June 2023
Among new protein structure predictors, the recently developed AlphaFold predictor relies on contact map in line with contact map potential based threading model that basically relies on fold recognition. In parallel, sequence similarity based homology model relies on homologue recognition. Both of these methods rely on sequence-structure or sequence-sequence similarity with protein with known structure in absence of which, as argued in the development of AlphaFold, the structure prediction becomes quite challenging.
View Article and Find Full Text PDFσ, an alternative sigma factor, is usually employed to tackle the general stress response in and other Gram-positive bacteria. This protein, involved in -mediated pathogenesis, is typically blocked by RsbW, an antisigma factor having serine kinase activity. σ, a σ-like sigma factor, harbors three conserved domains designated σ, σ, and σ.
View Article and Find Full Text PDFRsbW, an anti-sigma factor possessing kinase activity, is expressed by many Gram-positive bacteria including Staphylococcus aureus. To obtain clues about the domain structure and the folding-unfolding mechanism of RsbW, we have elaborately studied rRsbW, a recombinant S. aureus RsbW.
View Article and Find Full Text PDFFKBP22, a protein expressed by Escherichia coli, possesses PPIase (peptidyl-prolyl cis-trans isomerase) activity, binds FK506 (an immunosuppressive drug), and shares homology with Legionella Mip (a virulence factor) and its related proteins. To understand the domain structure and the folding-unfolding mechanism of Mip-like proteins, we investigated a recombinant E. coli FKBP22 (His-FKBP22) as a model protein.
View Article and Find Full Text PDFOf the three cold shock proteins expressed by Staphylococcus aureus, CspC is induced poorly by cold but strongly by various antibiotics and toxic chemicals. Using a purified CspC, here we demonstrate that it exists as a monomer in solution, possesses primarily β-sheets, and bears substantial structural similarity with other bacterial Csps. Aggregation of CspC was initiated rapidly at temperatures above 40 °C, whereas, the Gibbs free energy of stabilization of CspC at 0 M GdmCl was estimated to be +1.
View Article and Find Full Text PDFPreviously, various inhibitors of cell wall synthesis induced the drp35 gene of Staphylococcus aureus efficiently. To determine whether drp35 could be exploited in antistaphylococcal drug discovery, we cloned the promoter of drp35 (P(d)) and developed different biological assay systems using an engineered S. aureus strain that harbors a chromosomally-integrated P(d) - lacZ transcriptional fusion.
View Article and Find Full Text PDFPreviously, the repressor protein of mycobacteriophage L1 bound to two operator DNAs with dissimilar affinity. Surprisingly, the putative operator consensus sequence, 5'GGTGGa/cTGTCAAG, lacks the dyad symmetry reported for the repressor binding operators of lambda and related phages. To gain insight into the structure of the L1 repressor-asymmetric operator DNA complex, we have performed various in vitro experiments.
View Article and Find Full Text PDFThe primary sigma factor (sigma(A)) of Staphylococcus aureus, a potential drug target, was little investigated at the structural level. Using an N-terminal histidine-tagged sigma(A) (His-sigma(A)), here we have demonstrated that it exits as a monomer in solution, possesses multiple domains, harbors primarily alpha-helix and efficiently binds to a S. aureus promoter DNA in the presence of core RNA polymerase.
View Article and Find Full Text PDFThe temperate Staphylococcus aureus phage Phi11 harbors cI and cro repressor genes similar to those of lambdoid phages. Using extremely pure Phi11 Cro (the product of the Phi11 cro gene) we demonstrated that this protein possesses a single domain structure, forms dimers in solution at micromolar concentrations and maintains a largely alpha-helical structure even at 45 degrees C. Phi11 Cro was sensitive to thermolysin at temperatures ranging from 55-75 degrees C and began to aggregate at ~63 degrees C, suggesting that the protein is moderately thermostable.
View Article and Find Full Text PDFThe repressor protein and cognate operator DNA of any temperate Staphylococcus aureus phage have not been investigated in depth, despite having the potential to enrich the molecular biology of the staphylococcal system. In the present study, using the extremely pure repressor of temperate Staphylococcus aureus phage phi11 (CI), we demonstrate that CI is composed of alpha-helix and beta-sheet to a substantial extent at room temperature, possesses two domains, unfolds at temperatures above 39 degrees C and binds to two sites in the phi11 cI-cro intergenic region with variable affinity. The above CI binding sites harbor two homologous 15 bp inverted repeats (O1 and O2), which are spaced 18 bp apart.
View Article and Find Full Text PDFProteins expressed by the bacterial cold shock genes are highly conserved at sequence level and perform various biological functions in both the cold-stressed and normal cells. To study the effects of various agents on the cold shock genes of Staphylococcus aureus, we have cloned the upstream region of cspC from S. aureus Newman and found that the above region possesses appreciable promoter (P(c)) activity even at 37 degrees C.
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