| Comment |
Covalent linkages of various types formed between two proteins (interchain cross-links) or between two parts of the same protein (intrachain cross-links); except for cross-links formed by disulfide bonds, for which the "DISULFID" feature key is to be used. For an interchain cross-link, the location descriptor in the feature location element is the residue number of the amino acid cross-linked to the other protein. For an intrachain cross-link, the location descriptors in the feature location element are the residue numbers of the cross-linked amino acids in conjunction with the "join" location operator, e.g. 'join(42,50).' The NOTE qualifier indicates the nature of the cross-link; at least specifying the name of the conjugate and the identity of the two amino acids involved. Examples of values for the "NOTE" qualifier: 'Isoglutamyl cysteine thioester (Cys-Gln);' 'Beta-methyllanthionine (Cys-Thr);' and 'Glycyl lysine isopeptide (Lys-Gly) (interchain with G-Cter in ubiquitin)' |