{HEAD ~ Examples} of conservative substitutions with non conventional amino acids are described in {TAIL ~ Rosenberg} et al 
are described in
{ HEAD ~ Examples } of conservative substitutions with non conventional amino acids are described in { TAIL ~ Rosenberg } et al
HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH