Skip to main content
. Author manuscript; available in PMC: 2016 Nov 5.
Published in final edited form as: Cell. 2015 Oct 22;163(4):947–959. doi: 10.1016/j.cell.2015.10.016

Figure 7. Linear Tracking Model for Orientation-biased Usage of CACs in the Paired bona fide RSSs-containing Loop Domains.

Figure 7

(A) Linear map of a DEL-SJ-containing loop domain. (B) Activation of RAG by paired bona fide RSSs in the CTCF/cohesin-anchored loop domain. (C) One bona fide RSS may escape at a very low frequency leaving the activated complex. (D) A CAC in convergent orientation of the remaining bona fide RSS binds to RAG to facilitate cleavage or initiate unidirectional tracking. (E) Further tracking resulting in usage of another convergent CAC. (F) RAG tracking in the loop in either direction is stopped by the boundary formed by the CTCF/cohesin complex. (G) Joining products from pairing and cleavage between remaining bona fide RSS and convergent CACs. More details are in the text. Various modifications of this basic tracking model can be conceived to explain joining patterns of proximal V, D, and J segments in endogenous antigen receptor loci (not shown). See also Figure S7.