The DINGGG thermoprotein is membrane bound in the Crenarchaeon Sulfolobus solfataricus

Background Sulfolobus solfataricus N-terminus and other regions of the partial amino acid sequence of a thermoprotein exhibiting poly(ADP-ribose) polymerase activity suggest that it belongs to the DINGGG class of proteins that are often described as membrane bound. Our previous biochemical studies demonstrated that the thermoprotein is also strictly associated with DNA, and is only partially solubilized from cell homogenate. The present research is focused on the analysis of the sulfolobal DING thermozyme localization within the archaeal cell. Results Immunofluorescence microscopy evidenced the peripheral cell localization of Sulfolobal DING protein, along the plasma membrane hedge. Less intense, but clearly occurring, is the merge of Sulfolobus poly (ADP-ribose) polymerase with nucleoid. Anti-poly(ADP-ribose) polymerase immunoblottings clearly showed the occurrence of Sulfolobus thermozyme in membrane fractions as well as they confirmed its association with nucleoid DNA. Conclusions Fluorescent anti-PARP-1 antibodies showed that the PARPSso immunosignal localizes close to the membrane, at the periphery of cell, and that PARPSso green signal is also overlapping or strictly close to the nucleoid. Biochemical analyses confirmed that the thermozyme occurs in both membrane and nucleoid preparations.