PMC:1570349 / 18276-18817 JSONTXT

{"project":"2_test","denotations":[{"id":"16859561-10659856-1688452","span":{"begin":178,"end":180},"obj":"10659856"},{"id":"16859561-10659857-1688453","span":{"begin":181,"end":183},"obj":"10659857"},{"id":"16859561-12787501-1688454","span":{"begin":374,"end":376},"obj":"12787501"}],"text":"To understand design principles underlying biological systems, simple oscillatory and switch-like systems have been constructed experimentally. Several systems based on E. coli [24,25] have been successfully demonstrated. Recently, components of the Lac and Ntr systems have been used to construct a genetic clock that upon change in connectivity, exhibits switch behavior [26]. After ignoring the dynamics of the read-out gene, the system of three equations for the concentrations of mRNA (x1, x3, x5) and proteins (x2, x4, x6) is given as,"}