I think it may a bit more complex than simply yes or no. James McInterney
makes an interesting point about the lack of correlation in Sulfolobus,
but there are other cases where the 16S is lower in GC than the genome in
general. There may be a general correlation in most cases, but there are
certainly enough exceptions to warrent being very careful about such
conclusions.
Of course I dont have a single reference to back this up either, but if
you look at the halophile 16S genes and genomes, I think they bear this
out anecdotally.
Patrick
