Removing duplicate accession numbers and sorting alphabetica

[joeytogo]

HI,
I would like to remove duplicate accession numbers and the sequences associated with them. I would also like to sort sequences so that all of the same species group together and are sorted alphabetically. For example, below there are two ABV56639.Sdid sequences. Is there a way I could get textpad to find the duplicates and replace them with nothing?
Thanks, JB

>ABV56692.Sdev
FDRGYLSQYMVTDNEKMVADLENPYIL
>ABV56639.Sdid
FDRGYLSQYMVTDNEKMVADLEKPFIL
>ABV56639.Sdid
FDRGYLSQYMVTDNEKMVADLEKPFIL