So this is the pentaglycine shown here. It's this nitrogen that's going to form a bond with this carbon here. So this is an adjacent short peptide and the terminal amino acid E is the D alanine. And the next one in line is also the D alanine. And what this nitrogen does is it bonds with this carbon and once it forms a bond, it basically kicks off that terminal dalanine. And that's exactly what forms this green cross linkage that we basically show here.