This domain family is found in eukaryotes, and is typically between 231 and 255 amino acids in length. There is a single completely conserved residue P that may be functionally important. MKT1 is required for maintenance of K2 toxin above 30 degrees C in strains with the L-A-HN variant of the L-A double-stranded RNA virus of Saccharomyces cerevisiae. MKT1 is a 93 kDa protein with serine-rich regions and the retroviral protease signature, DTG. This family is the C terminal region of MKT1.

1: Sequence of MKT1, needed for propagation of M2 satellite dsRNA of the L-A virus of Saccharomyces cerevisiae. Vermut M, Widner WR, Dinman JD, Wickner RB; Yeast. 1994;10:1477-1479. PMID:7532890