Srm. Kyostio et Ra. Owens, IDENTIFICATION OF MUTANT ADENOASSOCIATED VIRUS REP PROTEINS WHICH AREDOMINANT-NEGATIVE FOR DNA HELICASE ACTIVITY, Biochemical and biophysical research communications, 220(2), 1996, pp. 294-299
Adeno-associated virus type 2 (AAV) Rep proteins have been postulated
to play a role in unwinding the 145-bp inverted terminal repeats durin
g AAV DNA replication. Previous studies showed that AAV Rep78 and Rep6
8 could unwind a DNA partial duplex of 26 bp. In this work it is demon
strated that nuclear extracts of human 293 cells containing wild-type
Rep68 can unwind partial DNA duplexes up to 160 bp long. Mutant Rep pr
oteins with either a histidine substituted for lysine 340 or a deletio
n of methionine 225 had no detectable helicase activity and inhibited
the helicase activity of wild-type Rep68 protein. This observation is
consistent with the model that the functional form of the Rep proteins
is a multimer.