GO curators, (2012-). Gene Ontology annotation based on absence of key sequence residues.  ( Link 1 )

FBrf0254415

FlyBase analysis

This describes a method for supplying a NOT-qualified, IKR-evidenced GO annotation to a gene product, when general sequence homology considerations would suggest a function or location, or a role in a biological process, but where a curator has determined that the absence of key sequence residues, known to be required for an expected activity or location, indicating the gene product is unlikely to be able to carry out the implied activity, involvement in a process or cellular component location. This reference should only be used used when an IKR-evidenced annotation is made based on curator judgement from manually reviewing the sequence of the gene product and where no publication can be found to support the curators conclusion. It is preferable to cite a peer-reviewed publication (such as a PubMed identifier) for IKR-evidenced annotations whenever possible. Curators will have carefully reviewed the sequence of the annotated protein, and established that the key residues known to be required for an expected activity or location are not present. Corresponds to GO_REF:0000047.