Hi I'm trying to model the N-terminus of mature canine Apolipoprotein A-I using Chimera. However the actual sequence in uniprot is not that of the mature protein. Here is the sequence: MKAALLTLAVLFLTGSQARHFWQQDEPQSPWDRVKDLATVYVDAVKDSGRDYVAQFEASA LGKQLNLKLLDNWDSLSSTVTKLREQIGPVTQEFWDNLEKETEVLRQEMSKDLEEVKQKV QPYLDDFQKKWQEEVELYRQKVAPLGSELREGARQKLQELQEKLSPLAEELRDRARTHVD ALRAQLAPYSDDLRERLAARLEALKEGGGASLAEYHARASEQLSALGEKARPALEDLRQG LLPVLESFKVSLLAAIDEATKKLNAQ The sequence of the mature form is: DEPQSPWDRVKDLATVYVDAVKDSGRDYVAQFEASA LGKQLNLKLLDNWDSLSSTVTKLREQIGPVTQEFWDNLEKETEVLRQEMSKDLEEVKQKV QPYLDDFQKKWQEEVELYRQKVAPLGSELREGARQKLQELQEKLSPLAEELRDRARTHVD ALRAQLAPYSDDLRERLAARLEALKEGGGASLAEYHARASEQLSALGEKARPALEDLRQG LLPVLESFKVSLLAAIDEATKKLNAQ According to how the sequence is labeled in uniprot the first aspartate residue of mature canine Apolipoprotein A-I starts at position 25, and this what Chimera uses. However, for the mature protein this should start at position 1. How can I change the numbering system so the first aspartate residue starts at position 1? I would be very glad for your advice. Thank you. Tiglath