IUUC-Xtr-132130 ENSXETG00000020830.4 K9J8C5 ubr4 Xenopus tropicalis IUUC-Xtr-132244 ENSXETG00000000961.3 F6ZZA4 ubr1 Xenopus tropicalis IUUC-Xtr-132690 ENSXETG00000000201.3 F6ZG62 ubr2 Xenopus tropicalis