Identification and Characterization of Novel Nucleoid Protein(NNP) in Anaerobic Growth Escherichia coli

Jun TERAMOTO
A systematic search for the regulation targets by YgiP, an uncharacterized LysR-family transcription factor in E. coli, has been performed using the genomic SELEX screening. A total of 333 independent clones have been isolated from 126 different loci in the E. coli genome. No consensus recognition sequence has been obtained after gel shift and DNase-I foot-printing assays, implying that YgiP is a DNA-binding protein with no sequence specificity as the major nucleoid proteins, HU and IHF. One
more » ... que activity of NNP is marked enhancement of the sensitivity of associated DNA to nucleolytic digestion. The intracellular level of NNP is very low in E. coli cells grown under aerobic conditions, leaving it hitherto unidentified as a nucleoid protein, but increased more than 100-fold as high as those of HU and IHF under anaerobic culture conditions. Taken together we propose that YgiP is a novel nucleoid protein (hence renamed to NNP) in anaerobic growth E. coli. When fully induced, NNP is located not only within the nucleoid but also in the cytoplasm as detected by indirect immuno-fluorescent microscopy. To get more insight into the mechanism
doi:10.15002/00005709 fatcat:eglxiy2jvfcafa6uco4335we4m