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Characterization of an unusual cold shock protein from Staphylococcus aureus
Author(s) -
Chanda Palas K.,
Bandhu Amitava,
Jana Biswanath,
Mondal Rajkrishna,
Ganguly Tridib,
Sau Keya,
Lee Chia Y.,
Chakrabarti Gopal,
Sau Subrata
Publication year - 2010
Publication title -
journal of basic microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.58
H-Index - 54
eISSN - 1521-4028
pISSN - 0233-111X
DOI - 10.1002/jobm.200900264
Subject(s) - staphylococcus aureus , cold shock domain , microbiology and biotechnology , shock (circulatory) , chemistry , biology , bacteria , biochemistry , medicine , genetics , gene , rna
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. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)