The ADP-ribosylation of Sulfolobus solfataricus Sso7 modulates protein/DNA interactions in vitro

• Published in: FEBS letters Vol. 583; no. 7; pp. 1154 - 1158
• Main Authors: Castellano, Sabrina, Farina, Benedetta, Faraone-Mennella, Maria Rosaria
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 02.04.2009
• Subjects: Adenosine Diphosphate - metabolism; Archaeal Proteins - metabolism; DNA binding; DNA, Archaeal - metabolism; DNA-Binding Proteins - metabolism; Poly(ADP-ribose) polymerase; Poly(ADP-ribose) Polymerases - metabolism; Protein Processing, Post-Translational - physiology; Protein Structure, Tertiary - physiology; Sso7; Sulfolobus solfataricus; Sulfolobus solfataricus - metabolism; Poly(ADP-ribose) polymerase; Sulfolobus solfataricus; DNA binding; Sso7
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/j.febslet.2009.03.003

The 7 kDa Sso7 is a basic protein particularly abundant in Sulfolobus solfataricus and is involved in DNA assembly. This protein undergoes in vitro ADP-ribosylation by an endogenous poly(ADP-ribose) polymerase-like enzyme. The circular dichroism spectrum of purified ADP-ribosylated Sso7 shows that this modification stabilizes the prevalent protein β-conformation, as suggested by shifting of negative ellipticity minimum to 220 nm. Moreover, a short ADP-ribose chain (up to 6-mers) bound to Sso7 is able to reduce drastically the thermoprotective and DNA condensing ability of the protein, suggesting a possible regulatory role of ADP-ribosylation in sulfolobal DNA organization.