passages.id: split_5_test_373_passage
passages.type: progene_text
passages.text: A highly stable structure has been identified comprised of peptides derived from the simian virus 5 ( SV5 ) F1 heptad repeat A , which abuts the hydrophobic fusion peptide ( peptide N-1 ) , and the SV5 F1 heptad repeat B , located 270 residues downstream and adjacent to the transmembrane domain ( peptides C-1 and C-2 ) .