I do wonder why you're trying to scrape HTML from this site when the life sciences community is actually very far ahead of the game when it comes to providing data in machine-readable formats.

Taking one of the proteins from your list...

use 5.010;
use RDF::Trine;
use RDF::QueryX::Lazy;

my $protein  = 'P61177';
my $pr_url   = sprintf 'http://purl.uniprot.org/uniprot/%s', $protein;

my $database = RDF::Trine::Model->new;
RDF::Trine::Parser->parse_url_into_model($pr_url => $database);

my $query = RDF::QueryX::Lazy->new(<<"QUERY");
SELECT *
WHERE {
    <$pr_url> rdfs:seeAlso ?fam_url .
    ?fam_url rdfs:comment ?family .
    FILTER regex(STR(?fam_url), "^http://purl\.uniprot\.org/interpro/"
+)
}
QUERY

my $results = $query->execute($database);
while (my $result = $results->next())
{
    say $result->{family}, q[ ], $result->{fam_url};
}
[download]

Running that produces the following output:

"Ribosomal_L22_bac-type" <http://purl.uniprot.org/interpro/IPR005727>
"Ribosomal_L22/L17_CS" <http://purl.uniprot.org/interpro/IPR018260>
"Ribosomal_L22" <http://purl.uniprot.org/interpro/IPR001063>