Practice 2. Definitions
   
 

Weight matrix:
Given a collection of known binding sites, a weight matrix is computed by measuring the frequency of every element in every position of the site (weight). Then, the score for any putative site is the sum of matrix values for that sequence (log likelihood scores).

Disadvantage:
A cut-off (threshold) value to filter is required. Different positions are supposed to make independent contributions to DNA-protein binding.

TACGAT TATAAT TATAAT GATACT TATGAT TATGTT

Weight matrix:
1 2 3 4 5 6
A 060340
C 001010
G 100300
T 505016




N E X T

Enrique Blanco García © 2002