Algorithms in bioinformatics (CSI 5126)=1Please don't print these lecture notes unless you really need

66MotivationN Y1Algorithms in bioinformatics (CSI 5126) I How to characterize motifs?A AI How to compare motifs?N-N’IN-N’ How to select amongst several motifs?Marcel TurcotteR(turcotte@site.uottawa.ca)N-N’ aN, R and Y are de ned by IUPAC-IUBN-N’School of Information Technology and Engineering R is A or G , i.e. [AG ]University of Ottawa N-N’ Y is T or C , i.e. [TC ]CanadaN-N’N is any, i.e. [ACGT ]N-N’ 3’ 0November 27, 2009 N is the complementNa5’ N www.chem.qmul.ac.uk/iubmb/misc/naseq.html1Please don’t print these lecture notes unless you really need to!Marcel Turcotte (turcotte@site.uottawa.ca) CSI 5126. Algorithms in bioinformatics Marcel Turcotte (turcotte@site.uottawa.ca) CSI 5126. Algorithms in bioinformaticsInformation theory UncertaintyThe information content measures the reduction of theuncertainty (also called entropy) after some message has beenI Information is based on the notion uncertainty about anreceived. In the case of motifs, the interpretation is \how much event | what symbol do you expect to nd at a giveninformation is gained by knowing that a sequence segmentposition of the sequence?matches a given motif".I Uncertainty is de ned as follows,Merriam-Webster Online about \entropy": MXH = P log Pi 2 i1 : ... usually considered to be a measure of thei=1system’s disorder ...3 : Chaos, disorganization, randomness.Marcel Turcotte (turcotte@site.uottawa.ca) CSI 5126. Algorithms in bioinformatics Marcel Turcotte (turcotte@site ...