/usr/share/msxpertsuite/massxpert/polSeqs/ is in msxpertsuite-data 4.1.0-1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/msxpertsuite/massxpert/polSeqs/17-mer-ps-po-dna-chimera.mxp
/usr/share/msxpertsuite/massxpert/polSeqs/beta-2-tubulin.mxp
/usr/share/msxpertsuite/massxpert/polSeqs/centrin-2-human.mxp
/usr/share/msxpertsuite/massxpert/polSeqs/cerulean-histag.mxp
/usr/share/msxpertsuite/massxpert/polSeqs/chicken-telokin.mxp
/usr/share/msxpertsuite/massxpert/polSeqs/citrin-fluorescent-protein.mxp
/usr/share/msxpertsuite/massxpert/polSeqs/cyan-fluorescent-protein-h148d-histag.mxp
/usr/share/msxpertsuite/massxpert/polSeqs/cyan-fluorescent-protein.mxp
/usr/share/msxpertsuite/massxpert/polSeqs/horse-myoglobin.mxp
/usr/share/msxpertsuite/massxpert/polSeqs/insulin-a-ox.mxp
/usr/share/msxpertsuite/massxpert/polSeqs/insulin-b-ox.mxp
/usr/share/msxpertsuite/massxpert/polSeqs/kunitz-inhibitor-human.mxp
/usr/share/msxpertsuite/massxpert/polSeqs/leu-enkephalin.mxp
/usr/share/msxpertsuite/massxpert/polSeqs/protein-1-letter.mxp
/usr/share/msxpertsuite/massxpert/polSeqs/protein-3-letters.mxp
/usr/share/msxpertsuite/massxpert/polSeqs/tev-protease-his-tag.mxp
/usr/share/msxpertsuite/massxpert/polSeqs/yellow-fluorescent-protein.mxp