# If the files are not too large...
# Read in the sequence file putting the data into a hash
use strict;
my %hash;
while (<DATA>) {
	chomp $_;
	my ($id,$protein) = /^gi\|(.+?)\|.+\|(.+)$/;  ## Save what you need 
	$hash{$1} = $2;
}

# Now use the second file to print out the hash
my @array2 = qw(13470319 13470331 15460001 13490216);
map { print "$hash{$_}\n"; } @array2;


__DATA__
gi|13490216|ref|NP_101899.1|protein for 216
gi|13470331|ref|NP_101896.1|protein for 331
gi|15460001|ref|NP_101898.1|protein for 001
gi|13470319|ref|NP_101897.1|protein for 319