Is there available a precomputed phylogenetic tree for 16S rRNA gene that has taxonomy information included for all levels not just the leaves? In principle I'm looking for a tree that has looks like (Escherichia(Escherichia coli(Ec K12, Ec O167))) but with branch lengths. I have found a few small ones, but I'm looking for the largest possible (RDP has an alignment with 1.3M sequences, GG 300K).
Yes, SILVA... I should probably mention that I hope I could avoid fighting with ARB software (badly written, crashes, requires weird versions of libraries). SILVA's official exports do not contain large trees.
There's a development version of ARB that is supposedly a lot better than the stable old one and used by basically everyone at Max Planck.
Finally it worked (uff, half of the time spent looking for compatible linux version). Thanks a lot for the pointer - export went smoothly.