pam - Return PAM scoring matrix

Syntax

ScoringMatrix = pam(N)
[ScoringMatrix, MatrixInfo] = pam(N)

... = pam(N, ...'Extended', ExtendedValue, ...)
... = pam(N, ...'Order', OrderValue, ...)

Arguments

N

Enter values 10:10:500. The default ordering of the output is A R N D C Q E G H I L K M F P S T W Y V B Z X *.

Entering a larger value for N to allow sequence alignments with larger evolutionary distances.

ExtendedValue

Property to add ambiguous characters to the scoring matrix. Enter either true or false. Default is false.

OrderValue

Property to control the order of amino acids in the scoring matrix. Enter a string with at least the 20 standard amino acids.

Description

ScoringMatrix = pam(N) returns a PAM scoring matrix for amino acid sequences.

[ScoringMatrix, MatrixInfo] = pam(N) returns a structure with information about the PAM matrix. The fields in the structure are Name, Scale, Entropy, Expected, and Order.

... = pam(N, ...'PropertyName', PropertyValue, ...) calls pam with optional properties that use property name/property value pairs. You can specify one or more properties in any order. Each PropertyName must be enclosed in single quotation marks and is case insensitive. These property name/property value pairs are as follows:


... = pam(N, ...'Extended', ExtendedValue, ...)
if Extended is true, returns a scoring matrix with the 20 amino acid characters, the ambiguous characters, and stop character (B, Z, X, *), . If Extended is false, only the standard 20 amino acids are included in the matrix.

... = pam(N, ...'Order', OrderValue, ...) returns a PAM matrix ordered by the amino acid sequence in Order. If Order does not contain the extended characters B, Z, X, and *, then these characters are not returned.

PAM50 substitution matrix in 1/2 bit units, Expected score = -3.70, Entropy = 2.00 bits, Lowest score = -13, Highest score = 13.

PAM250 substitution matrix in 1/3 bit units, Expected score = -0.844, Entropy = 0.354 bits, Lowest score = -8, Highest score = 17.

Examples

Return a PAM matrix with N = 50.

PAM50 = pam(50)

PAM250 = pam(250,'Order','CSTPAGNDEQHRKMILVFYW')

See Also

Bioinformatics Toolbox functions: blosum, dayhoff, gonnet, nwalign, swalign

  


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