Sequences were identified for 275 putative orphan enzymes, most frequently by fixing database errors.

Sequences were found for 275 putative orphan enzymes (25% of the total) by searching through the literature, sequence databases, and patents. Approximately half of the orphans for which sequences could be found were “annotation updates,” in which the sequence for the enzyme in major databases was annotated with no activity, with a less specific activity, with an incorrect activity that was in the same general class as the correct one, or with another correct activity that the enzyme also carries out. The remaining orphans fell into the “data inconsistency” category. Orphan enzymes in this category were in some way annotated to sequence data, but a lack of an EC number or a nomenclature mismatch meant that searching these databases for the activity did not yield any sequence data.

通过检索文献、序列数据库及专利文献，本研究共获取275种推定孤儿酶（putative orphan enzyme）的序列信息，占总数量的25%。在可获得序列数据的孤儿酶中，约半数属于"注释更新"类别：即主流数据库中该酶的序列仅被注释为无活性、活性特异性较低、与正确活性同属一个大类的错误活性，或是该酶同时具备的另一项正确活性。剩余的孤儿酶则归入"数据不一致"类别。此类孤儿酶虽已在一定程度上关联至序列数据并完成注释，但因缺少EC编号（Enzyme Commission number）或命名法不匹配，通过活性检索对应数据库时无法获得相应序列信息。