>4if6A (A:) observed residues (from ATOM records)
mrkkrkdintiedavkllqeckkiivltgagvsvscgipdfrsrdgiyarlavdfpdlpd
pqamfdieyfrkdprpffkfakeiypgqfqpslchkfialsdkegkllrnytqnidtleq
vagiqriiqchgsfatasclickykvdceavrgdifnqvvprcprcpadeplaimkpeiv
ffgenlpeqfhramkydkdevdllivigsslkvrpvalipssiphevpqilinreplphl
hfdvellgdcdviinelchrlggeyaklccnpvklsei