E2/Other family is a collection of unconventional E2s which does not contain the UBC domain. E2s for ubiquitin-like (UBL) conjugates involved in autophagy such as Atg8/12 conjugates are included (1). UFC1, the E2 for Ufm1, is also in this family (2).

1. van Wijk, S.J. and Timmers, H.T. (2010) The family of ubiquitin-conjugating enzymes (E2s): deciding between life and death of proteins. FASEB J., 24, 981-993.PMID: 19940261

2. Komatsu, M., Chiba, T., Tatsumi, K., Iemura, S., Tanida, I., Okazaki, N., Ueno, T., Kominami, E., Natsume, T. and Tanaka, K. (2004). A novel protein-conjugating system for Ufm1, a ubiquitin-fold modifier. EMBO J., 23, 1977-1986.PMID: 15071506