- Cis-acting
In the field of
molecular biology , cis-acting generally means "acting from the samemolecule " ("i.e.",intramolecular ). It may be considered the opposite oftrans-acting which generally means "acting from a different molecule" ("i.e.", intermolecular).In the context of transcription regulation, cis-acting elements are usually considered to be
DNA sequences that, viatranscription factor s or other trans-acting elements or factors, regulate the expression ofgene s on the samechromosome . [cite book
last = Watson
first = James D.
coauthors = Caudy, Amy A, Myers, Richard M., Witkowski, Jan A.
authorlink = James D. Watson
title = Recombinant DNA: Genes and Genomes - A Short Course
publisher = Cold Spring Harbor Press
date = 2007
pages = 57-58
isbn = 0-7167-2866-4 ] The "operator" in thelac operon is an example of a cis-acting regulatory sequence. This DNA sequence is bound by thelac repressor which in turn prevents transcription of the adjacent genes on the same DNA molecule. The lac operator is thus considered to "act in cis" on the regulation of the nearby genes. The operator itself doesn't code for anyprotein orRNA .ee also
*
Cis-regulatory element
*Trans-acting References
Wikimedia Foundation. 2010.
