Using R to import specific records from a PDB file I'm using R and I'm trying to import specific records from a PDB file (e.g. HETNAM, HETSYN). Unfortunately, it seems the read.pdb function of either biomaRt or Rpdb aren't capable of it.

Any ideas?

Thanks
If your file is in PDB format as the one shown here in .pdb format then you can simply extract your desired fields using sed which is a programming language used to parse and transform text. As for this structure i.e 6C4A in .pdb format HETNAM and HETSYN can be extracted using sed as follows:

sed  -n -e '/HETNAM/ p' -e '/HETSYN/ p'  6C4A.pdb

HETNAM     EJA S-[(1Z)-2-CARBOXY-N-HYDROXYETHANIMIDOYL]-L-CYSTEINE              
HETNAM     PYR PYRUVIC ACID                                                     
HETNAM      MG MAGNESIUM ION                                                    
HETNAM     3NP 3-NITROPROPANOIC ACID                                            
HETNAM     PEG DI(HYDROXYETHYL)ETHER                                            
HETNAM     EPE 4-(2-HYDROXYETHYL)-1-PIPERAZINE ETHANESULFONIC ACID              
HETSYN     EPE HEPES