Study On The Yigp Gene Of Escherichia Coli

yigP gene exists in many species, and the sequence is relatively conservatived. In E. coli, yigP gene (GenelD:948915) locates between ubiE and ubiB, which are responsible for the biosynthesis of ubiquinone. GeneBank annotates yigP as a protein-coding gene, based on the analysis of its sequence by softwares.Our early studies have shown that yigP is a housekeeping gene for E. coli. The fragment downstream of yigP is enough to play the function of wild-type yigP. YigP gene would have its own promoter.The focus of this work is to study the basic informations and functions of yigP. We first made a frame shift mutation of the open reading frames (ORFs) within the functional fragments, but the mutation does not affect its function. This exclude the possibility of yigP to be a protein-coding genes. One of our early study show that yigP gene on a plasmid can also complement the defected yigP on chromosome. This means yigP is not function as a cis-regulatory elements. All of those suggest that yigP may be a ncRNA gene in E. coli.By real-time quantitative PCR, we find that yigP strongly expressed in the logarithmic growth phase, and the expression rapidly decreased in the steady-state phase.Transcriptional start site of yigP has been identified by5’RACE, and two transcriptional stop sites are identified by3’RACE, one locates at the end of yigP, the other has extended into ubiB which is the downstream gene of yigP.Using bioinformatics techniques, we predict29candidates of yigP targets in the level of E.coli genome. And verify these candidates by stimulate plsmid/reporter plasmid system. Finally, we discover that the expression of ssuA and kdsD has been significantly enhanced by yigP.