Required for nuclear membrane fusion during karyogamy. Belongs to the KAR5 family. Truncated N-terminus. Contains ambiguous sequence between ORF C6_01010W_A and C6_01020W_A. Used assembly 19 sequence to merge the 2 ORFs. Contains ambiguous sequence between ORF C6_01010W_A and C6_01020W_A. Used assembly 19 sequence to merge the 2 ORFs.