def highest_seq_similarity(crys_seqs: list, query: AASeq) -> (AASeq, float):
"""
:param crys_seqs: list of AASeq instances of crystalised seqs
:param query: a query AASeq
:return: the most sequence-similar sequence
"""
best_seq, best_iden = AASeq(), 0.0
for seq in crys_seqs:
iden_ = query.aligned_identity(seq)
if iden_ > best_iden:
best_iden = iden_
best_seq = seq
return best_seq, best_iden
