Members of this protein family average about 650 amino acids in length, with an N-terminal region related to reverse transcriptases. The only characterized member is AbiA, with reported activity as an abortive infection protein for phage defense in Lactococcus lactis and (heterologously) in Streptococcus thermophilus.
Jiyao W et al.(2023). "The conserved domain database in 2023.",