use strict;
use warnings;
use Data::Dumper;
use JSON;

my $json = <<JSON;
[ { 
		"PROT_SIZE": "1620", 
		"PROT_NAME": "ALK", 
		"PROT_ID": "Q9UM73", 
		"COVERTURA": [ { 
				"PSTART": "1084", 
				"PEND": "1405" }, { 
				"PSTART": "1571", 
				"PEND": "1589" } 
				] 
  }, 
	{ "PROT_SIZE": "273", 
		"PROT_NAME": "XPA", 
		"PROT_ID": "P23025", 
		"COVERTURA": [ { 
				"PSTART": "67", 
				"PEND": "77" }, { 
				"PSTART": "98", 
				"PEND": "210" } 
        ]
	} 
]
JSON

my $j = JSON->new->decode($json);
for my $s (@$j) {
		next unless $s->{PROT_NAME} eq 'XPA';
		for my $p (@{$s->{COVERTURA}}) {
				print $p->{PSTART},"\n";
		}
}