bio3d (version 2.2-4)

aa123: Convert Between 1-letter and 3-letter Aminoacid Codes

Description

Convert between one-letter IUPAC aminoacid codes and three-letter PDB style aminoacid codes.

Usage

aa123(aa)
aa321(aa)

Arguments

aa

a character vector of individual aminoacid codes.

Value

A character vector of aminoacid codes.

Details

Standard conversions will map ‘A’ to ‘ALA’, ‘G’ to ‘GLY’, etc. Non-standard codes in aa will generate a warning and return ‘UNK’ or ‘X’.

References

Grant, B.J. et al. (2006) Bioinformatics 22, 2695--2696. For a description of IUPAC one-letter codes see: http://www.chem.qmul.ac.uk/iupac/AminoAcid/ For more information on PDB residue codes see: http://ligand-expo.rcsb.org/ld-search.html

See Also

read.pdb, read.fasta, pdbseq

Examples

# Simple conversion
aa123(c("D","L","A","G","S","H"))
aa321(c("ASP", "LEU", "ALA", "GLY", "SER", "HIS"))

## Not run: 
# # Extract sequence from a PDB file's ATOM and SEQRES cards
# pdb <- read.pdb("1BG2") 
# s <- aa321(pdb$seqres)                   # SEQRES
# a <- aa321(pdb$atom[pdb$calpha,"resid"]) # ATOM
# 
# # Write both sequences to a fasta file
# write.fasta(alignment=seqbind(s,a), id=c("seqres","atom"), file="eg2.fa")
# 
# # Alternative approach for ATOM sequence extraction
# pdbseq(pdb)
# pdbseq(pdb, aa1=FALSE )
# ## End(Not run)