cis and trans - (Dec/29/2005 )

would anybody of you be so kind to give me a definition for cis- and trans- acting elements,
can't find a satisfying answer on the net.
thanks.

You got me curious enough to go back to some early text books....

Cis-acting elements are DNA sequences in the vicinity of the target gene that are required for gene expression - [i]these are on the same strand as the gene to be translated and directly affect translation /i]

Trans-acting elements also often known as factors - are usually considered to be proteins, that bind to or interact with the cis-acting sequences to control gene expression - thus they control gene expression indirectly and are reffered to as trans.

the book, Gene VII by Benjamin Lewin or whatever the current edition is probably best explains it.