Viewing DNA sequence. In the screenshot above, several biological parts are connected together. However, the promoter named "laczya" is regulating two other gene segments. The regulation is shown by the two dotted arrows. Since the promoter is regulating two genes, it is implied that there are two copies of this promoter, one upstream of each gene that it regulates. This is one method of showing regulation in an abstract way in the synthetic biology community . The color coded circles reflect the first and last parts in the displayed sequence. The individual sequences are loaded from RegulonDB  via a Python script. The sequence attribute is only available for items of specific families, as described by the family tree of biological parts. The sequence viewing window is provided by a small plug-in.