R: Amino Acid Metric Solution using R (Atchley et al 2005)
AAMetric
R Documentation
Amino Acid Metric Solution using R (Atchley et al 2005)
Description
Atchley et al 2005 performed factor analysis on a set of Amino Acid Indices (AA54) and inferred
a 5 factor latent variable structure relating amino acid characteristics using SAS. An equivalent analysis
was performed using factor.pa.ginv from the HDMD package in R. Based on the
relationship between factors and variable descriptions, the latent
variables are defined as
Factor1 (PAH): Polarity, Accessibility, Hydrophobicity; Factor2 (PSS): Propensity for Secondary Structure;
Factor3 (MS) : Molecular Size; Factor4 (CC): Codon Composition; Factor5 (EC): Electrostatic Charge.
While the Factor Analysis loadings were the same, R and SAS calculated scores slightly differently.
AAMetric are scores from the R factor analysis which convey the similarities and differences
among amino acids (rows) for each latent variable (columns).
Format
Rows are alphabetized Amino Acids and the 5 columns are factors where
Factor1 (PAH): Polarity, Accessibility, Hydrophobicity; Factor2 (PSS): Propensity for Secondary Structure;
Factor3 (MS) : Molecular Size; Factor4 (CC): Codon Composition; Factor5 (EC): Electrostatic Charge.
Details
54 Amino Acid Indices were selected from www.genome.jp/aaindex to quantify Amino Acid Similarities.
Using Factor Analysis on 5 factors, interpretable latent variables were determined to quantify
Amino Acid attributes. These are the scores from factor analysis calculated by factor.pa.ginv in R.
Source
Method similar to Atchley, W. R., Zhao, J., Fernandes, A. and Drueke, T. 2005. Solving the sequence "metric" problem: Proc. Natl. Acad. Sci. USA 102: 6395-6400.
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> library(HDMD)
Loading required package: psych
Loading required package: MASS
> png(filename="/home/ddbj/snapshot/RGM3/R_CC/result/HDMD/AAMetric.Rd_%03d_medium.png", width=480, height=480)
> ### Name: AAMetric
> ### Title: Amino Acid Metric Solution using R (Atchley et al 2005)
> ### Aliases: AAMetric
> ### Keywords: datasets
>
> ### ** Examples
>
> data(AAMetric)
Warning message:
In data(AAMetric) : data set 'AAMetric' not found
> plot(AAMetric[,1], AAMetric[,2], pch = AminoAcids)
>
> cor(AAMetric, AAMetric.Atchley)
pah pss ms cc ec
pah 0.99530421 0.0736871113 -0.12587574 -0.11889767 0.03117132
pss 0.05875309 0.9826834483 -0.08629297 0.06208317 0.04304136
ms -0.31217404 -0.2978205891 0.37953125 -0.26553117 0.20126148
cc -0.16603923 0.0340235286 -0.16418210 0.98779448 -0.12086778
ec -0.04245232 -0.0001209467 -0.27474905 0.09063324 -0.66015554
>
>
>
>
>
> dev.off()
null device
1
>