Fig. 6: A mechanical model of RNase H1-mediated bidirectional processive RNA–DNA hybrids cleavage.
From: RPA transforms RNase H1 to a bidirectional exoribonuclease for processive RNA–DNA hybrid cleavage
The RNA–DNA cleavage by RNase H1 (brown) cyclically proceeds in the 3′-to-5′ direction. Within each catalytic cycle, unwinding approximately 6-bp hybrids occurs before two 3-nt excisions in each catalytic cycle (green box). The presence of RPA (purple) stimulates the 3′-to-5′ exonucleolytic cleavage of RNase H1 (grey box) and stimulates its 5′-to-3′ exoribonuclease activity by pre-separation of the hybrid duplex (pink box). The blue arrows indicate the movement direction and rate of RNase H1.
