RecBCD steps:

1. Binds to end of dsdna and unwinds via helicase activity. 2. Degrades both directions strands via exonuclease activity. 3. Each step is 23 bps long "quantum inch worm". 4. When meets the x-site: 3 to 5 exonuclease is inhibited, 5 to 3 exonuclease is stimulated. 5. produces ssdna 3 end tail wehre RecA binds.