Novel targets and cofactors for LysM, a transcriptional regulator of the Leucine-responsive Regulatory Protein family in Sulfolobus

Archaeal transcription apparatus resembles eukaryal transcription polymerase II transcription system, but archaeal transcriptional regultors resembles bacterial Lrpl-like regulators. This raises interesting questions concerning the interplay between the archaeal transcription machinery and regulators that will modulate its activity. In our study, LysM proteins belonging to the large family of Lrp-like proteins from model organisms Sulfolobus solfataricus and Sulfolobus acidocaldaris were studied to decipher the molecular mechanism of LysM regulation and to identify the new binding sites for the regulatortargets on the genome of S.ulfolobus solfataricus. Therefore, we performedby applying a LysM-specific nanobody-based chromatin immunoprecipitation assay combined with microarray hybridization (ChIP-chip) and in silico target site prediction using an energy based position weight matrix. T, and these findings were validated with in vitro binding. Since some of the newly identified LysM targets are invloved in amino acid s biosynethesis and transport, all twenty naturally occuring20 L-amino acids and some structural analogues of lysine structure analogues and precurosors in lysine biosynthesis were tested for their potential role as effector molecule of LysM binding applied to the investgate effects on promoter region of gltB (Sso0684) control region.