Table 3.

Summary of models

Filament assembly model	Distinct details of model
	Growth mechanism, DNA cleavagea	Maximum size of ROO filaments
5EO	Ends only	5
4EO	Ends only	4
4BM	Breaks in the middle	4

^a The ends-only growth mechanism is where only a single SgrAI–DNA complex (i.e. ES₄₀ or EP₄₀) adds to an ROO filament (run-on oligomer of SgrAI–DNA complexes) at a time. Dissociation similarly occurs only one SgrAI–DNA complex at a time and only from either end of the ROO filament. The breaks-in-the-middle mechanism refers to a growth mechanism where dissolution or dissociation of an ROO filament may occur at any position within the ROO filament, at any juncture between adjacent SgrAI–DNA complexes (i.e. ES₄₀ or EP₄₀). Association also may occur via the association between two ROO filaments of any size and/or single SgrAI–DNA complexes.