/usr/include/ncbi/algo/blast/api/ is in libncbi6-dev 6.1.20120620-7.
This file is owned by root:root, with mode 0o755.
..
/usr/include/ncbi/algo/blast/api/blast_api.h
/usr/include/ncbi/algo/blast/api/blast_format.h
/usr/include/ncbi/algo/blast/api/blast_input.h
/usr/include/ncbi/algo/blast/api/blast_message_api.h
/usr/include/ncbi/algo/blast/api/blast_mtlock.h
/usr/include/ncbi/algo/blast/api/blast_options_api.h
/usr/include/ncbi/algo/blast/api/blast_prelim.h
/usr/include/ncbi/algo/blast/api/blast_returns.h
/usr/include/ncbi/algo/blast/api/blast_seq.h
/usr/include/ncbi/algo/blast/api/blast_seqalign.h
/usr/include/ncbi/algo/blast/api/blast_tabular.h
/usr/include/ncbi/algo/blast/api/dust_filter.h
/usr/include/ncbi/algo/blast/api/hspfilter_queue.h
/usr/include/ncbi/algo/blast/api/repeats_filter.h
/usr/include/ncbi/algo/blast/api/seqsrc_multiseq.h
/usr/include/ncbi/algo/blast/api/seqsrc_readdb.h
/usr/include/ncbi/algo/blast/api/twoseq_api.h