IUUC-Xtr-132359 ENSXETG00000027365.2 F7EKS7 ube2v1 Xenopus tropicalis IUUC-Xtr-132332 ENSXETG00000014566.1 F6WIM3 tsg101 Xenopus tropicalis IUUC-Xtr-131975 ENSXETG00000004856.3 Q28G19 ube2v2; ube2v1; TGas122e12.1-001 Xenopus tropicalis