Molecular Genetics
Other Pages
Signal elements
dobefmolecdaiularsqueihgensvweticskiprovsvillmmdescheplemolasusyretpb
Biomolecular signals consist of two parts: a signaling molecule and a receptor of the signal. The signal molecule is usually diffusible and acts int rans, whereas the receptor for signals to DNA is often a sequence in the DNA.
-
An organism's genome contains all the information needed to build
that organism. The information is present in the tape-like linear
base sequence of the genomic nucleic acid. Comprehending the information
requires:
- Identification of signal elements is not simple because:
- a) signal elements are embedded in extraneous information.
- b) signal elements may consist of non-contiguous nucleotides.
- Numerous approaches are employed to identify signal elements.
- Signal elements usually act only on the nucleotide sequence to
which they are attached. They are said to act "in cis". Signal elements can be turned on and off by interacting with signalling factors. These factors are usually protein molecules. Since the protein factors are free to diffuse in the cell they act on their target signal elements regardless of whether their genes are attached to the same genome segment as the signal element or not. Such protein factors are called "trans-acting factors". Understanding the "cis" "trans" concept is important for understanding rgulation in molecular genetics.
dobefmolecdaiularsqueihgensvweticskiprovsvillmmdescheplemolasusyretpb
molec ular gen etics pro vi des ple asu re
Last | Overview | Top | Next
This is page 21 of Molecular Genetics by Ulrich Melcher, © 1997, 1998, 2001
E-mail inquiries to U. Melcher------------Last Updated: 13 N ovember, 2003