Characterization of an unusual cold shock protein from Staphylococcus aureus

Abstract

Of 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 +1.6 kcal mol(-1), indicating a less stable protein. Surprisingly, CspC showed stable binding with ssDNA carrying a stretch of more than three thymine bases and binding with such ssDNA had not only stabilized CspC against proteolytic degradation but also quenched the fluorescence intensity from its exposed Trp residue. Analysis of quenching data indicates that each CspC molecule binds with ∼5 contiguous thymine bases of the above ssDNA and binding is cooperative in nature.

Identification and characterization of an operon, msaABCR, that controls virulence and biofilm development in Staphylococcus aureus

“…Based on sequence homology, S. aureus produces three proteins (CspA, CspB, and CspC) that may be associated with cold-shock stress [33-35]. However, Anderson et al .…”

“…The msaB gene encodes a 66-amino acid polypeptide that showed homology with cold-shock proteins of E. coli (CspA, 60%) and Bacillus subtilis (CspB, 76%). Based on sequence homology, S. aureus produces three proteins (CspA, CspB, and CspC) that may be associated with cold-shock stress [ 33 - 35 ]. However, Anderson et al .…”

Adaptive Metabolism in Staphylococci: Survival and Persistence in Environmental and Clinical Settings

“…Transmission electron microscopy (TEM) evaluations of Staphylococcus aureus, Staphylococcus epidermidis, and Staphylococcus lugdunensis clinical isolates exposed to 4°C for 8 weeks showed thickened CW structures associated with significant alterations in amino acid (AA) profiles in comparison to controls [ 12 ]. Modifications in AA content in relation to temperature adaptation were thought to be linked to an increase in CW-associated proteins, particularly cold-shock proteins which are essential in maintaining the integrity of this structure and functionality in cold temperatures [ 18 – 20 ]. The staphylococcal CM is also rich in fatty acids (FAs) and lipid content, essential to its adaptive functions in the presence of host defences, antimicrobial challenges, and acclimatization to environmental fluctuations [ 21 ].…”

RNA-Seq-Based Analysis of Cold Shock Response in Thermoanaerobacter tengcongensis, a Bacterium Harboring a Single Cold Shock Protein Encoding Gene

“…Some members of the CSP family, such as Eco CspA and B. subtilis CspB, are induced by cold shock and function as RNA chaperones to prevent the formation of mRNA secondary structures, therefore facilitating efficient ribosomal binding, protein elongation, and translation termination [29] . Eco CspA also significantly accumulates on entry into log growth phase [30] , and Staphylococcus aureus CspC is strongly induced by some antibiotics and toxic chemicals [31] . Therefore, CSPs are essential to survival not only during cold shock, but also when cells encounter other stressors.…”