Perl Regex Translation.

[mccalla]

Hi,

I am new to perl.
I just inherited a perl script that has this

  while ($input_sequence =~ /(  (.)\2{7,} | (..)\3{3,} | (...)\4{3,} | (.{4,100})\5{2,}  )/g)

I've been trying to decipher exactly what this translate too.
Can any experts out there help me.

(input sequence contains a bunch of letters and number.
i.e.,

>gi|208965091|g b|ACI31834.1| factor Y-binding protein [Neisseria meningitidis]
MNRTAFCCFSLTAAL ILTACSSGGGGVAAD IGAGLADALTAPLDH KDKGLQSLTLDQSVR KNEKLKLAAQ
GAEKTYGNGDSLNTG KLKNDKVSRFDFIRQ IEVDGQLITLESGEF QIYKQDHSAVVALQI EKINNPDKID
SLINQRSFLVSGLGG EHTAFNQLPSGKAEY HGKAFSSDDPNGRLH YSIDFTKKQGYGRIE HLKTPEQNVE
LASAELKADEKSHAV ILGDTRYGGEEKGTY HLALFGDRAQEIAGS ATVKIREKVHEIGIA GKQ

Thanks in advance,
mccalla

[KevinADC]

The regular expression is checking for consecutive characters as in AAA or CCCCC and how many times those consecutive sets of characters occur in the string.