Off topic:Extracting fasta sequences from headers

Question

[Audrey]

Hi all,

I have a list of fasta headers :

>Strain1_XX
>Strain2_YY
>Strain3_ZZ

I have a multifasta file :

>Strain1_XX
AAAA
>Strain2_YY
AAAA
>Strain3_ZZ
AAAA

And I would like to extract specifically the strain number 2 meaning its fasta sequence + headers.

I tried using awk because I know how powerful this tool is but I can't seemed to find how to do it.

If you have any ideas, the help would be so appreciated.

Thank you !