Domain organization and activity of Rep proteins. (A)
Domain structure of TYLCV Rep, wheat dwarf virus (WDV) RepA, porcine
circovirus 2 (PCV2) Rep, plasmid pC194 RepA, bacteriophage ΦX174 A,
transposon IS91 TnpA, and AAV2 Rep68 proteins. The catalytic domains
are displayed in gray, and the conserved sequence motifs (28) are
labeled I, II, and III. The oligorimerization domains of TYLCV Rep and
WDV RepA are shown in dark gray. (B) Activity assays of
TYLCV Rep proteins. (Left) Western blot analysis of a
12% denaturing gel. (Right) A 15% gel after
Coomassie staining. About 20–40% of Rep becomes covalently
linked to the 5′ end of the 15-nt cleavage product (marked by arrow)
under these conditions. The sizes of molecular weight markers are
indicated between the panels.