#!/usr/bin/perl
use warnings;
use strict;

my $line = "BOGUS PPI3_SYNY3 276 aa linear BCT 13-NOV-2019\n";

if (my ($bogus, $acids) = $line =~ /BOGUS\s+([A-Z0-9_]+) ([0-9]+ [a-z]+)/) {
    print "bogus: $bogus\nNumber of acids: $acids\n"
}